Questions · Page 2 of 6

M.C.Q

MCQ 511 Mark
IF $\text{AB}⊥\text{BC}$ and $\angle\text{BAC} = \angle\text{BCA},$ then which of the following statements is true?
  • A
    AB ≠ BC
  • B
    AB = AC
  • C
    AB = BC
  • D
    BC = AC
Answer
  1. AB = BC
    Solution:
    ABC is a right-angled isosceles triangle with $\angle\text{BAC} = \angle\text{BCA},$ and hence sides opposite to equal angles must be equal. Hence, we can say that AB = BC.
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MCQ 521 Mark
In $\triangle\text{ABC}$ and $\triangle\text{DEF}$ its is given that $\angle\text{B}=\angle\text{E}$ and $\angle\text{C}=\angle\text{F}$ in order that $\triangle\text{ABC}≅\triangle\text{DEF}$ we must have,
  • A
    AC = DE
  • B
    BC = EF
  • C
    AB = DF
  • D
    $\angle\text{A}=\angle\text{D}$
Answer
  1. BC = EF
    Solution:
    In $\triangle\text{ABC}$ and $\triangle\text{DEF}$
    $\angle\text{B}=\angle\text{E}$ and $\angle\text{C}=\angle\text{F}$
    For congruence, BC = EF
    Therefore by AAS axiom
    $\triangle\text{ABC}≅\triangle\text{DEF}$
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MCQ 541 Mark
In triangles ABC and PQR three equality relations between some parts are as follows: AB = QP, $\angle\text{B} = \angle\text{P},$ BC = PR. State which of the congruence conditions applies:
  • A
    AAS
  • B
    ASA
  • C
    SAS
  • D
    SSS
Answer
  1. SAS
    Solution:
    Two sides and included angle are equal and is SAS axiom.
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MCQ 551 Mark
In a $\triangle\text{ABC},$ if $​\angle\text{B} = ​\angle\text{C} = 45^\circ,$ which is the longest side?
  • A
    AC
  • B
    None of these.
  • C
    BC
  • D
    CA
Answer
  1. BC
    Solution:
    We know that sum of all angles of a triangle is 180°
    $\angle\text{A} + \angle\text{B} + \angle\text{C} = 180^\circ$
    $\angle\text{B} = \angle\text{C} = 45^\circ$
    $\angle\text{A} + 45^\circ + 45^\circ = 180^\circ$
    $\angle\text{A} + 90^\circ = 180^\circ$
    $\angle\text{A} = 180^\circ - 90^\circ$
    $\angle\text{A} = 90^\circ$
    So, angle A is the largest and the side opposite to the greatest angle is the longest so, side BC is the longest.
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MCQ 571 Mark
  • A
    55º
  • B
    65º
  • C
    75º
  • D
    50º
Answer
  1. 75º
    Solution:
    We have,
    $∴\ \angle\text{ABD}+\angle\text{ABC}=180^\circ$ [$∵$ E is a straight line]
    $⇒125^\circ+\angle\text{ABC}=180^\circ$
    $⇒\angle\text{ABC}=55^\circ$
    Also,
    $\angle\text{ACE}+\angle\text{ACB}=180^\circ$
    $⇒130^\circ+\angle\text{ACB}=180^\circ$
    $⇒\angle\text{ACB}=50^\circ$
    $∴\angle\text{BAC}+\angle\text{ABC}+\angle\text{ACB}=180^\circ$ [Sum of the angles of a triangle]
    $⇒\angle\text{BAC}+55^\circ+50^\circ=180^\circ$
    $⇒\angle\text{BAC}=75^\circ$
    $⇒\angle\text{A}=75^\circ.$
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MCQ 591 Mark
  • A
    65º
  • B
    45º
  • C
    55º
  • D
    35º
Answer
  1. 65º
    Solution:
    Since BAE is a straight line, we have
    $\angle\text{BAC}+\angle\text{CAE}=180^\circ$ .....(Supplementary angles)
    $\Rightarrow\angle\text{BAC}+135^\circ=180^\circ$
    $\Rightarrow\angle\text{BAC}=45^\circ$
    Since CBD is a straight line, we have
    $\angle\text{ABD}+\angle\text{ABC}=180^\circ$ ....(Supplmenetary angles)
    $\Rightarrow110^\circ+\angle\text{ABC}=180^\circ$
    $\Rightarrow\angle\text{ABC}=70^\circ$
    In $\triangle\text{ABC},$ we have
    $\angle\text{BAC}+\angle\text{ABC}+\angle\text{ACB}=180^\circ$ .....(Angle sum property)
    $\Rightarrow45^\circ+70^\circ+\angle\text{ACB}=180^\circ$
    $\Rightarrow\angle\text{ACB}=65^\circ$
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MCQ 601 Mark
Two sides of a triangle are of length 4cm and 2.5cm. The length of the third side of the triangle cannot be:
  • A
    6cm
  • B
    6.5cm
  • C
    5.5cm
  • D
    6.3cm
Answer
  1. 6.5cm
    Solution:
    The sum of any two sides of a triangle is greater than the third side.
    Since, 4cm + 2.5cm = 6.5cm
    The length of third side of a triangle cannot be 6.5cm.
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MCQ 611 Mark
In $\triangle\text{AOC}$ and $\triangle\text{XYZ},\ \angle\text{A}=\angle\text{X},\ \angle\text{AO} = \angle\text{XY},\ \angle\text{AC} = \angle\text{XZ},$ then by which congruence rule $\triangle\text{AOC}\cong\triangle\text{XYZ}?$
  • A
    RHS
  • B
    SAS
  • C
    ASA
  • D
    SSS
Answer
  1. SAS
    Solution:
    According to SAS criterion, if the corresponding sides and their included angles are equal, then the triangles are congruent. Here, in $\triangle\text{AOC}$ and $\triangle\text{XYZ},$ AO = XY, and AC = XZ are the corresponding sides and $\angle\text{A}=\angle\text{X}$ are included angles, Hence, $\triangle\text{AOC}\cong\triangle\text{XYZ},$ by SAS.
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MCQ 621 Mark
The triangle is not possible with the given measurements:
  • A
    5.4cm, 2.3cm, 3.1cm
  • B
    6cm, 7cm, 7cm
  • C
    3cm, 5cm, 5cm
  • D
    8.3cm, 3.4cm, 6.1cm
Answer
  1. 5.4cm, 2.3cm, 3.1cm
    Solution:
    In a triangle, the sum of any two sides must be greater than the third side and here 2.3 + 3.1 = 5.4 and hence, the triangle is not possible with the given measurements.
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MCQ 631 Mark
In a $\triangle\text{ABC},$ if $\angle\text{A}−\angle\text{B}=42^\circ$ and $\angle\text{B}−\angle\text{C}=21^\circ$ then $\angle\text{B} = ?$
  • A
    63º
  • B
    32º
  • C
    95º
  • D
    53º
Answer
  1. 53º
    Solution:
    Let,
    $\angle\text{A}−\angle\text{B}=42°...\ \text{(i)}$ and
    $\angle\text{B}−\angle\text{C}=21^\circ ...\ \text{(ii)}$
    Adding (i) and (ii),we get
    $\angle\text{A}−\angle\text{C}=63° ...\ \text{(iii)}$
    $\angle\text{B}=\angle\text{A}−42^\circ$ [using (i)]
    $\angle\text{C}=\angle\text{A}−63^\circ$ [Using (iii)]
    $∴\angle\text{A}+\angle\text{B}+\angle\text{C}=180^\circ$ [Sum of the angles of a triangle]
    $⇒\angle\text{A}+\angle\text{A}−42^\circ+\angle\text{A}−63^\circ=180^\circ$
    $⇒3\angle\text{A}−105^\circ=180^\circ$
    $⇒3\angle\text{A}=285^\circ$
    $∴\angle\text{B}=(95−42)^\circ$
    $⇒\angle\text{B}=53^\circ$
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MCQ 651 Mark
If $\triangle\text{ABC}≅\triangle\text{PQR}$ and $\triangle\text{ABC}$ is not congruent to $\triangle\text{RPQ},$ then which of the following is not true:
  • A
    QR = BC
  • B
    AB = PQ
  • C
    BC = PQ
  • D
    AC = PR
Answer
  1. BC = PQ
    Solution:
    According to the condition given in the question,
    If $\triangle\text{ABC}≅\triangle\text{PQR}$ and $\triangle\text{ABC}$ is not congruent to $\triangle\text{RPQ}.$
    Then, clearly BC ≠ PQ
    $\therefore$ It is false
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MCQ 661 Mark
  • A
    60º
  • B
    50º
  • C
    25º
  • D
    40º
Answer
  1. 60º
    Solution:
    Let $ \angle\text{A}=(3\text{x})^\circ,\ \angle\text{B}=(2\text{x})^\circ$ and $\angle\text{C}=\text{x}^\circ$
    Then,
    3x + 2x + x = 180º [Sum of the angles of a triangle]
    ⇒ 6x = 180º
    ⇒ x = 30º
    Hence, the angles are
    $\angle\text{A}=3×30^\circ=90^\circ,\ \angle\text{B}=2×30^\circ=60^\circ$ and $\angle\text{C}=30^\circ$
    Side BC of triangle ABC is produced to E.
    $\therefore\ \angle\text{ACE}=\angle\text{A}+\angle\text{B}$
    $⇒\angle\text{ACD}+\angle\text{ECD}=90^\circ+60^\circ$
    $⇒90^\circ+\angle\text{ECD}=150^\circ$
    $⇒\angle\text{ECD}=60^\circ$
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MCQ 671 Mark
What is the sum of the angles of a quadrilateral?
  • A
    260º
  • B
    360º
  • C
    180º
  • D
    90º
Answer
  1. 360º
    Solution:
    For a quadrilateral
    Number of sides (n) = 4
    Sum of interior angles = (n - 2) × 180º
    p = (4 - 2) × 180º
    p = 2 × 180º
    p = 360º
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MCQ 691 Mark
In the following, write the correct answer.
If AB = QR, BC = PR and CA = PQ, then:
  • A
    $\triangle\text{ABC}\cong\triangle\text{QRP}$
  • B
    $\triangle\text{CBA}\cong\triangle\text{PRQ}$
  • C
    $\triangle\text{BAC}\cong\triangle\text{RQP}$
  • D
    $\triangle\text{PQR}\cong\triangle\text{BCA}$ 
Answer
  1. $\triangle\text{CBA}\cong\triangle\text{PRQ}$
    Solution:
    We know that, if is congruent to, then sides of $\triangle\text{RST}$ fall on corresponding equal sides of angles of fall on corresponding equal angles.
    Here, given AB = QR, BC = PR and CA = PQ, which shows that AB covers QR, BC covers PR and CA covers PQ i.e., A correspond to Q, B correspond to R and C correspond to P.
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MCQ 701 Mark
  • A
    AB < AD
  • B
    AB = AD
  • C
    AB > AD
  • D
    Cannot be determined
Answer
  1. AB > AD
    Solution:
    Given $\text{AB > AC}$
    $\therefore\angle\text{ACB}>\angle\text{ABC}$ ...(We know that, if two sides of a triangle unequal, then the longer side has the greater angle opposite to it.)
    $\angle\text{ADB}>\angle\text{ACD}$ ...(Exterior angle of a triangle is greater that the interior opposite angles)
    $\therefore\angle\text{ADB}>\angle\text{ACB}>\angle\text{ABC}$
    $\therefore\angle\text{ADB}>\angle\text{ABD}$
    $\therefore\text{AB > AD}$
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MCQ 711 Mark
  • A
    35º
  • B
    45º
  • C
    50º
  • D
    60º
Answer
  1. 60º
    Solution:
    In $\triangle\text{ABC},$
    $\angle\text{BCA}+\angle\text{CAB}+\angle\text{ABC}=180^\circ$
    $\Rightarrow3\text{y}^\circ+\text{x}^\circ+5\text{y}^\circ=180^\circ$
    $\Rightarrow8\text{y}^\circ+\text{x}^\circ=180^\circ\dots(1)$
    Also, $5\text{y}^\circ=180^\circ-7\text{y}^\circ$
    $\Rightarrow12\text{y}^\circ=180^\circ$
    $\Rightarrow\text{y}^\circ=15^\circ$
    From (1), $\text{x}^\circ=180^\circ-8\text{y}^\circ$
    $\Rightarrow\text{x}^\circ=180^\circ-8\times15^\circ$
    $\Rightarrow\text{x}^\circ=60^\circ$
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MCQ 721 Mark
In $\angle\text{ABC}$ and $\angle\text{DEF},$ AB = DE and $\angle\text{A} = \angle\text{D}.$ Then, the two triangles will be congruent by SAS axiom if:
  • A
    BC = EF
  • B
    AC = DF
  • C
    AC = DE
  • D
    BC = DE
Answer
  1. AC = DF
    Solution:
    The SAS rule states that:
    If two sides and the included angle of one triangle are equal to two sides and included angle of another triangle, then the triangles are congruent.
    Here, in $\angle\text{ABC},$ the two sides are AB and AC and the included angle is $\angle\text{A}.$ For $\angle\text{DEF},$ the two corresponding sides are DE and DF and the included angle is $\angle\text{D}.$
    Hence, the two triangles will be congruent by SAS axiom if AC = DF.
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MCQ 741 Mark
  • A
    20º
  • B
    50º
  • C
    60º
  • D
    70º
Answer
  1. 50º
    Solution:
    EC || AB And, CD is transverse to it.
    Now $\angle\text{ECD}=\angle\text{AOD}=70^\circ$ (Corresponding angles)
    In $\triangle\text{OBD}$
    $\angle\text{OBD}+\angle\text{BOD}+\angle\text{ODB}=180^\circ$
    $\angle\text{BOD}=180^\circ-\angle\text{AOD}=180^\circ-70^\circ=110^\circ$
    So $\angle\text{OBD}=180^\circ-\angle\text{BOD}-\angle\text{ODB}$
    $=180^\circ-110^\circ-20^\circ$
    $=50^\circ$
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MCQ 751 Mark
In triangles ABC and PQR, if $\angle\text{A}=\angle\text{R},\ \angle\text{B}=\angle\text{P}$ and AB = RP, then which one of the following congruence conditions applies:
  • A
    SSS
  • B
    RHS
  • C
    ASA
  • D
    SAS
Answer
  1. ASA
    Solution:
    Since, the two adjacent angles and the contained side are shown equal while proving the two triangles congruent. Hence, by A.S.A. theorem the two triangles can be proved congruent.
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MCQ 761 Mark
  • A
    50º
  • B
    60º
  • C
    70º
  • D
    80º
Answer
  1. 50º
    Solution:
    Since, $\triangle\text{ABC}$ and $\triangle\text{PQR}$ are similar triangles.
    then, $\angle\text{B} = \angle\text{Q} = 83^\circ$
    Thus, in $\triangle\text{ABC},$
    $\angle\text{C} = 180^\circ - (\angle\text{A} + \angle\text{B})$
    or, $\angle\text{C} = 180^\circ - (47^\circ + 83^\circ)$
    $\angle\text{C}=50^\circ$
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MCQ 771 Mark
  • A
    50º
  • B
    65º
  • C
    57.5º
  • D
    70º
Answer
  1. 57.5º
    Solution:
    As BC = AC, therefore triangle ABC is an isoscelestriangle.
    Given $\angle\text{ACD} = 115^\circ,\ \angle\text{ACB} = 180 - 115 = 65^\circ$ (Linear Pair)
    As AC = BC, therefore $\angle\text{A} =\angle\text{B}$
    As sum of all the three angles of atriangle is 180º
    Therefore. $\angle\text{A}+\angle\text{B} +\angle\text{ACB} = 180^\circ$
    $\angle\text{A} =\angle\text{B}=57.5^\circ$
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MCQ 781 Mark
  • A
    50º
  • B
    57.5º
  • C
    70º
  • D
    65º
Answer
  1. 50º
    Solution:
    $\angle\text{ACD} = 115^\circ,\ \angle\text{ACB} = 180-115=65^\circ$ (Linear Pair)
    Since, It is given that AB = AC, then $\angle\text{ABC} = \angle\text{ACB}$ (Isosceles trangle property)
    As $\angle\text{ACB} = 65^\circ,$ therefore $\angle\text{ACB} = 65^\circ$
    Sum of all the three angles of triangle = 180º, therefore $\angle\text{ABC} + \angle\text{ACB} + \angle\text{A} = 180^\circ$
    $\angle\text{A} = 180 - 65 - 65 = 50^\circ$
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MCQ 791 Mark
  • A
    100°
  • B
    115°
  • C
    130°
  • D
    120°
Answer
  1. 115°
    Solution:
    In $\triangle\text{ABC}$ we have:
    $\angle\text{A}+\angle\text{B}+\angle\text{C}=180^\circ$ [Sum of the angles of a trianlge]
    $⇒50^\circ+\angle\text{B}+\angle\text{C}=180^\circ$
    $⇒\angle\text{B}+\angle\text{C}=130^\circ$
    $\Rightarrow\ \frac{1}{2}\angle\text{B}\ +\ \frac{1}{2}\angle\text{C}=65^\circ\ ...\ (\text{i})$
    In $\triangle\text{OBC},$ we have:
    $\angle\text{OBC}+\angle\text{OCB}+\angle\text{BOC}=180^\circ$
    $\Rightarrow\ \frac{1}{2}\angle\text{B}\ +\ \frac{1}{2}\angle\text{C}\ +\ \angle\text{BOC}=180^\circ$
    $⇒65^\circ+\angle\text{BOC}=180^\circ$
    $⇒\angle\text{BOC}=115^\circ.$
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MCQ 821 Mark
If AB = QR, BC = RP and CA = PQ, then which of the following holds?
  • A
    $\triangle\text{ABC}\cong\triangle\text{PQR}$
  • B
    $\triangle\text{CBA}\cong\triangle\text{PQR}$
  • C
    $\triangle\text{CAB}\cong\triangle\text{PQR}$
  • D
    $\triangle\text{BCA}\cong\triangle\text{PQR}$
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MCQ 831 Mark
  • A
    18
  • B
    25
  • C
    22
  • D
    32
Answer
  1. 22
    Solution:
    $\text{AB} ⊥ \text{BC}$
    $⇒\ \angle\text{ABC}=90^\circ$
    $\angle\text{CAB}=32^\circ$ (Opposite angles)
    Now, in $\triangle\text{ABD}$
    $\angle\text{DAB }= \text{x}^\circ+32^\circ$
    $\angle\text{ABD}=90^\circ$
    $\angle\text{BDA }= \text{x}^\circ+14^\circ$
    In a $\triangle,$ sum of all angles = 180°
    $⇒ \angle\text{DAB} + \angle\text{ABD} + \angle\text{BDA} = 180^\circ$
    $⇒\text{x}^\circ + ^\circ32°+90^\circ + \text{x}^\circ+14^\circ = 180^\circ$
    $⇒\ 2\text{x}^\circ = 180^\circ - 136^\circ$
    $⇒\ 2\text{x}^\circ = 44$
    $⇒\ \text{x}^\circ= 22$
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MCQ 841 Mark
  • A
    It is 1 : 1
  • B
    It is 1 : 2
  • C
    It is 2 : 3
  • D
    It is 2 : 1
Answer
  1. It is 1 : 1
    Solution:
    In $\triangle\text{ABC}$
    $\text{AB = AC}$
    $\therefore \angle\text{ABC} = \angle\text{ACB}$ (angles opposite to equal sides of a triangle are equal) ...(1)
    In $\triangle\text{DBC},$
    $\text{DB = DC},$
    $\therefore \angle\text{DBC} = \angle\text{DCB}$ (angles opposite to equal sides of a triangle are equal) ...(2)
    subtract 2 from 1
    $\angle\text{ABC}-\angle\text{DBC} = \angle\text{ACB}-\angle\text{DCB}$ (equals subtracted from equals gives equal)
    $= \angle\text{ABD} = \angle\text{ACD}$
    Divide both the sides by $\triangle\text{ACD}$
    $\Rightarrow\frac{\angle\text{ABD}}{\angle\text{ACD}}=1$
    $\therefore \angle\text{ABD} : \angle\text{ACD}=1:1$
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MCQ 851 Mark
  • A
    50º
  • B
    55º
  • C
    65º
  • D
    75º
Answer
  1. 75º
    Solution:
    Since DE is a straights line,
    $\angle\text{ACB}+\angle\text{ACE}=180^\circ$
    $\Rightarrow\angle\text{ACB}+130^\circ=180^\circ$
    $\Rightarrow\angle\text{ACB}=50^\circ$
    In $\triangle\text{ABC},$
    $\angle\text{ABD}=\angle\text{BAC}+\angle\text{ACB}$ ......(Exterior angle is equal to sum of the remote interior angles)
    $\Rightarrow125^\circ=\angle\text{BAC}+50^\circ$
    $\Rightarrow\angle\text{BAC}=75^\circ$
    that is, $\angle\text{A}=75^\circ.$
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MCQ 861 Mark
The length of two sides of a triangle are 7 units and 10 units. Which of the following length can be the length of the third side?
  • A
    3cm
  • B
    19cm
  • C
    17cm
  • D
    13cm
Answer
  1. 13cm
    Solution:
    As per the rule in a triangle, sum of any 2 sides should be greater than the third side. So, the lenght of the third side should be 13, since with 7, 10 and 13 we have 7 + 10 > 13, 7 + 13 > 10 and 13 + 10 > 7.
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MCQ 871 Mark
  • A
    80º
  • B
    100º
  • C
    40º
  • D
    90º
Answer
  1. 100º
    Solution:
    In $\triangle\text{RST}$
    $\angle\text{R} + \angle\text{S} + \angle\text{T} = 180^\circ$
    ⇒ 2aº + xº + 2bº = 180º
    ⇒ xº = 180º - 2(a + b)º ... (i)
    Now, in $\triangle\text{ROT}$
    $\angle\text{ORT} + \angle\text{ROT} + \angle\text{OTR} = 180^\circ$
    ⇒ aº + 140º + bº = 180º
    ⇒ (a + b)º = 180º - 140º = 40º ...(ii)
    From eq. (i) and (ii)
    xº = 180º − 2(40º)
    ⇒ x = 100º
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MCQ 881 Mark
In $\triangle\text{ABC}$ and 6PQR, AB = PR and $\angle\text{A}=\angle\text{P}.$ Then, the two triangles will be congruent by SAS axiom if:
  • A
    BC = QR
  • B
    BC = PQ
  • C
    AC = PQ
  • D
    AC = QR
Answer
  1. AC = PQ
    Solution:
    $\angle\text{A}$ is included between AB and AC and LP is included between PQ and PR and corresponding sides must be equal. Since AB = PR, hence AC = PQ for the given triangles to be congruent by SAS axiom.
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MCQ 891 Mark
Find the measure of each exterior angle of an equilateral triangle.
  • A
    110º
  • B
    100º
  • C
    150º
  • D
    120º
Answer
  1. 120º
    Solution:
    We know that in equilateral triangle each angle is 60º
    And we know sum of interior angle and exterior angle is 180º
    Let exterior angle be x
    60º + x = 180º
    x = 180º - 60º
    x = 120º
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MCQ 901 Mark
The sum of the interior angles of a triangle is:
  • A
    270º
  • B
    360º
  • C
    180º
  • D
    90º
Answer
  1. 180º
    Solution:
    For a triangle,
    Number of sides (n) = 3
    Sum of interior angles = (n - 2) × 180º
    = (3 - 2) × 180º
    = 1 × 180º
    = 180º
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MCQ 911 Mark
An exterior angle of a triangle is equal to 100º and two interrior opposite angles are equal. Each of these angles is equal to:
  • A
    75º
  • B
    80º
  • C
    40º
  • D
    50º
Answer
  1. 50º
    Solution:
    Let the two interior opposite angles be xº each.
    Now, the exterior angle is equal to the sum of the two interior opposite angles.
    xº + xº = 180º
    ⇒ 2xº = 100º
    ⇒ xº = 50º
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MCQ 921 Mark
In a triangle ABC, $\angle\text{B} = 35^\circ$ and $\angle\text{C} = 60^\circ,$ then the shortest side is:
  • A
    BC
  • B
    AB and BC
  • C
    AC
  • D
    AB
Answer
  1. AC
    Solution:
    Side opposite to smallest angle is shortest side angles of triangle are 35, 60 and 85.
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MCQ 931 Mark
Side BC of a triangle ABC has been produced to a point D such that $\angle\text{ACD}=120^\circ.$ If $\angle\text{B}=\frac{1}{2}\angle\text{A},$ then $\angle\text{A}$ is equal to :
  • A
    80º
  • B
    75º
  • C
    60º
  • D
    90º
Answer
  1. 80º
    Solution:
    $\angle\text{B}=\frac{1}{2}\angle\text{A}$
    $\angle\text{ACD}$ is an exterior angle.
    $\Rightarrow\angle\text{A}+\angle\text{B}=\angle\text{ACD}$
    $\Rightarrow\angle\text{A}=\frac{1}{2}\angle\text{A}=120^\circ$
    $\Rightarrow\frac{3\angle\text{A}}{2}=120^\circ$
    $\Rightarrow3\angle\text{A}=240^\circ$
    $\Rightarrow\angle\text{A}=80^\circ$
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MCQ 941 Mark
In $\triangle\text{PQR},\ \angle\text{P} = 60^\circ,\ \angle\text{Q} = 50^\circ.$ Which side of the triangle is the longest?
  • A
    PQ
  • B
    QR
  • C
    None
  • D
    PR
Answer
  1. PQ
    Solution:
    In $\triangle\text{PQR},\ \angle\text{P} = 60^\circ,\ \angle\text{Q} = 50^\circ.$
    Now, by angle sum property, $\angle\text{P} +\angle\text{Q} +\angle\text{R} = 180^\circ$
    $60^\circ + 50^\circ + \angle\text{R} = 180^\circ$
    or, $\angle\text{R} = 180^\circ - 110^\circ = 70^\circ$
    So, $\angle\text{R}$ is the largest angle and the side opposite to it, i.e, PQ will be the longest side.
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MCQ 961 Mark
In triangles ABC and PQR, if $\angle\text{A}=\angle\text{R},\angle\text{B}=\angle\text{P}$ and $\text{AB}=\text{RP},$ then which one of the following congruence conditioins applies:
  • A
    SAS
  • B
    ASA
  • C
    SSS
  • D
    RHS
Answer
  1. ASA
    Solution:
    From given conditions,
    $\angle\text{B}=\angle\text{P}$
    $\angle\text{A}=\angle\text{R}$
    And the side containing then is also equal
    i.e $\text{AB}=\text{PR}$
    So ASA property.
    Hence, correct option is (b).
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MCQ 981 Mark
It is given that$\triangle\text{ABC}\cong\triangle\text{FDE}$ in which AB = 5cm, $\angle\text{B}=40^{\circ},\angle\text{A}=80^{\circ}$and FD = 5cm. Then, which of the following is true?
  • A
    $\angle\text{D}=60^{\circ}$
  • B
    $\angle\text{E}=60^{\circ}$
  • C
    $\angle\text{F}=60^{\circ}$
  • D
    $\angle\text{D}=80^{\circ}$
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MCQ 991 Mark
  • A
    1 : 1
  • B
    2 : 1
  • C
    1 : 2
  • D
    None of these
Answer
  1. 1 : 1
    Solution:
    In $\triangle\text{ABC},$
    $\text{AB = AC}\Rightarrow\angle\text{ABC}=\angle\text{ACB}...(\text{i})$
    In $\triangle\text{OBC},$
    $\text{OB = OC} \Rightarrow\angle\text{OBC}=\angle\text{OCB}...(\text{ii})$
    Subtraction (ii) from (i), we get
    $\Rightarrow\angle\text{ABO}=\angle\text{ACO}$
    So, $\angle\text{ABO}:\angle\text{ACO}=1:1$
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MCQ 1001 Mark
In a $\triangle\text{ABC},$ if $\angle\text{A} = 60^\circ, \ \angle\text{B} = 80^\circ$ and the bisectors of $\angle\text{B}$ and $\angle\text{C}$ meet at O, the $\angle\text{BOC} =$
  • A
    120º
  • B
    150º
  • C
    30º
  • D
    60º
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M.C.Q - Page 2 - Maths STD 9 Questions - Vidyadip