Question 11 Mark
In the following, state if the statement is true $(T)$ or false $(F)$: Every right triangle is scalene.
AnswerFalse.
A right triangle can also be an isosceles triangle.
View full question & answer→Question 21 Mark
Fill in the blank with the correct word/ symbol to make it a true statement: A triangle has _____ angles.
AnswerA triangle has three angles.
View full question & answer→Question 31 Mark
Fill in the blank with the correct word/ symbol to make it a true statement: A triangle whose one angle is a right angle is known as _________.
AnswerA triangle whose one angle is a right angle is known as a right triangle.
View full question & answer→Question 41 Mark
Fill in the blank with the correct word/ symbol to make it a true statement: A triangle has _____ sides.
AnswerA triangle has three sides.
View full question & answer→Question 51 Mark
In Figure, the length (in cm) of each side has been indicated along the side. State for each triangle angle whether it is scalene, isosceles or equilateral:
AnswerThis triangle is an equilateral triangle because all its three sides are equal.
View full question & answer→Question 61 Mark
In Figure, the length (in cm) of each side has been indicated along the side. State for each triangle angle whether it is scalene, isosceles or equilateral:
AnswerThis triangle is an isosceles triangle because two of its sides are equal.
View full question & answer→Question 71 Mark
In the following, the measures of three angles are given. State in which cases the angles can possibly be those of a triangle: $59^\circ , 72^\circ , 61^\circ $
Answer$59^\circ , 72^\circ , 61^\circ $ is not equal to $180^\circ $ Therefore not a triangle.
View full question & answer→Question 81 Mark
Fill in the blank with the correct word/ symbol to make it a true statement: A triangle whose all the sides are equal is known as ________.
AnswerA triangle whose all the sides are equal is known as an equilateral triangle.
View full question & answer→Question 91 Mark
In the following, state if the statement is true $(T)$ or false $(F)$: A triangle has three sides.
View full question & answer→Question 101 Mark
Take three collinear points $A, B$ and $C$ on a page of your note book. Join $AB. BC$ and $CA$. Is the figure a triangle? If not, why?
AnswerNo, the figure is not a triangle. By definition a triangle is a plane figure formed by three non-parallel line segments.
View full question & answer→Question 111 Mark
Fill in the blank with the correct word/ symbol to make it a true statement: A triangle has ________ parts.
AnswerA triangle has six (three sides + three angles) parts.
View full question & answer→Question 121 Mark
There are five triangles. The measures of some of their angles have been indicated. State for each triangle whether it is acute, right or obtuse.
AnswerThis is a right triangle because one of its angles is $90^\circ $.
View full question & answer→Question 131 Mark
In the following, state if the statement is true $(T)$ or false $(F)$: The interior of a triangle includes its vertices.
AnswerFalse.
The interior of a triangle is the region enclosed by the triangle and the vertices are not enclosed by the triangle.
View full question & answer→Question 141 Mark
$P$ is a point in the interior of $\triangle \text{ABC}$ as shown in Fig. State which of the following statements are true $(T)$ or false $(F):$
AnswerFalse.
We know that the sum of any two sides of a triangle is greater than the third side: it is not true for the given triangle.
View full question & answer→Question 151 Mark
In the following, state if the statement is true $(T)$ or false $(F)$: Any three line-segments make up a triangle.
AnswerFalse.
Any three non-parallel line segments can make up a triangle.
View full question & answer→Question 161 Mark
In the following, the measures of three angles are given. State in which cases the angles can possibly be those of a triangle: $45^\circ $, $61^\circ , 73^\circ $
Answer$45^\circ , 61^\circ , 73^\circ $ is not equal to $180^\circ $ Therefore not a triangle.
View full question & answer→Question 171 Mark
In the following, state if the statement is true $(T)$ or false $(F)$: Each acute triangle is equilateral.
AnswerFalse.
Each acute triangle is not an equilateral triangle, but each equilateral triangle is an acute triangle.
View full question & answer→Question 181 Mark
In Figure, the length (in cm) of each side has been indicated along the side. State for each triangle angle whether it is scalene, isosceles or equilateral:
AnswerThis triangle is a scalene triangle because no two sides are equal.
View full question & answer→Question 191 Mark
In the following, state if the statement is true $(T)$ or false $(F)$: The triangular region includes the vertices of the corresponding triangle.
AnswerTrue.
The triangular region includes the interior region and the triangle itself.
View full question & answer→Question 201 Mark
$P$ is a point in the interior of $\triangle \text{ABC}$ as shown in Fig. State which of the following statements are true $(T)$ or false $(F)$
:
AnswerFalse.
We know that the sum of any two sides of a triangle is greater than the third side: it is not true for the given triangle.
View full question & answer→Question 211 Mark
In the following, state if the statement is true $(T)$ or false $(F)$: An equilateral triangle is isosceles also.
AnswerTrue.
In an equilateral triangle, any two sides are equal.
View full question & answer→Question 221 Mark
Take three non-collinear points $A. B$ and $C$ on a page of your notebook. Join $AB, BC$ and $CA$. What figure do you get? Name the triangle. Also, name. The angle opposite to side $AB$
View full question & answer→Question 231 Mark
There are five triangles. The measures of some of their angles have been indicated. State for each triangle whether it is acute, right or obtuse.
AnswerThis is an obtuse triangle because one of its angles is $110^\circ $, which is greater than $90^\circ $.
View full question & answer→Question 241 Mark
Take three non-collinear points $A. B$ and $C$ on a page of your notebook. Join $AB, BC$ and $CA$. What figure do you get? Name the triangle. Also, name. The vertex opposite to side $BC$
View full question & answer→Question 251 Mark
In the following, the measures of three angles are given. State in which cases the angles can possibly be those of a triangle: $30^\circ , 20^\circ , 125^\circ $
Answer$30^\circ , 20^\circ , 125^\circ $ is not equal to $180^\circ $ Therefore not a triangle.
View full question & answer→Question 261 Mark
Fill in the blank with the correct word/ symbol to make it a true statement: A triangle has ______ vertices.
AnswerA triangle has three vertices.
View full question & answer→Question 271 Mark
In the following, state if the statement is true $(T)$ or false $(F)$:
No isosceles triangle is obtuse.
AnswerFalse.
An isosceles triangle can be an obtuse triangle, a right triangle or an acute triangle.
View full question & answer→Question 281 Mark
Fill in the blank with the correct word/ symbol to make it a true statement: A triangle whose one angle is more than 90' is known as _________.
AnswerA triangle whose one angle is more than $90'$ is known as an obtuse triangle.
View full question & answer→Question 291 Mark
In the following, state if the statement is true $(T)$ or false $(F)$: The vertices of a triangle are three collinear points.
AnswerFalse.
The vertices of a triangle are three non-collinear points.
View full question & answer→Question 301 Mark
Take three non-collinear points $A. B$ and $C$ on a page of your notebook. Join $AB, BC$ and $CA$. What figure do you get? Name the triangle. Also, name. The side opposite to $\angle\text{B}$
View full question & answer→Question 311 Mark
There are five triangles. The measures of some of their angles have been indicated. State for each triangle whether it is acute, right or obtuse.
AnswerThis is an acute triangle because all its angles are acute angles (less than 90°).
View full question & answer→Question 321 Mark
In the following, state if the statement is true $(T)$ or false $(F)$: A triangle may have four vertices.
AnswerFalse.
A triangle has three vertices.
View full question & answer→Question 331 Mark
Fill in the blank with the correct word/ symbol to make it a true statement: A triangle whose no two sides are equal is known as ________.
AnswerA triangle whose no two sides are equal is known as a scalene triangle.
View full question & answer→Question 341 Mark
Take three non-collinear points $A. B$ and $C$ on a page of your notebook. Join $AB, BC$ and $CA$. What figure do you get? Name the triangle. Also, name.
The side opposite to vertex $B$.
View full question & answer→Question 351 Mark
In the following, the measures of three angles are given. State in which cases the angles can possibly be those of a triangle:
$63^\circ , 37^\circ , 80^\circ $
Answer$63^\circ , 37^\circ , 80^\circ = 180^\circ $
Angles form a triangle.
View full question & answer→Question 361 Mark
Fill in the blank with the correct word/ symbol to make it a true statement:
A triangle whose all the angles are of measure less than $90'$ is known as _________.
AnswerA triangle whose all the angles are of measure less than $90'$ is known as an acute triangle.
View full question & answer→Question 371 Mark
$P$ is a point in the interior of $\triangle \text{ABC}$ as shown in Fig. State which of the following statements are true $(T)$ or false $(F)$:
AnswerTrue.
We know that the sum of any two sides of a triangle is greater than the third side: it is true for the given triangle.
View full question & answer→Question 381 Mark
There are five triangles. The measures of some of their angles have been indicated. State for each triangle whether it is acute, right or obtuse.
AnswerThis is an obtuse triangle because one of its angles is $120^\circ $, which is greater than $90^\circ .$
View full question & answer→Question 391 Mark
There are five triangles. The measures of some of their angles have been indicated. State for each triangle whether it is acute, right or obtuse.
AnswerThis is a right triangle because one of its angles is $90^\circ $.
View full question & answer→Question 401 Mark
In Figure, the length (in cm) of each side has been indicated along the side. State for each triangle angle whether it is scalene, isosceles or equilateral: 
Answer This triangle is an isosceles triangle because two of its sides, viz. PQ and PR, are equal.
View full question & answer→Question 411 Mark
In the following, the measures of three angles are given. State in which cases the angles can possibly be those of a triangle:
$45^\circ , 45^\circ , 90^\circ $
Answer$45^\circ , 45^\circ , 90^\circ = 180^\circ $
Angles form a triangle.
View full question & answer→Question 421 Mark
In Figure, the length (in cm) of each side has been indicated along the side. State for each triangle angle whether it is scalene, isosceles or equilateral: 
Answer This triangle is a scalene triangle because no two sides are equal.
View full question & answer→Question 431 Mark
Fill in the blank with the correct word/ symbol to make it a true statement: A triangle whose two sides are equal is known as ________.
AnswerA triangle whose two sides are equal is known as an isosceles triangle.
View full question & answer→Question 441 Mark
The sides of certain triangles are given below. Determine which of them are right triangles.
$a=9 cm, b=16 cm$ and $c=18 cm$
View full question & answer→Question 451 Mark
The sides of certain triangles are given below. Determine which of them are right triangles.
$a=7 cm, b=24 cm$ and $c=25 cm$
View full question & answer→Question 461 Mark
If the sides of a triangle are 3 cm, 4 cm and 6 cm long, determine whether the triangle is rightangled triangle.
Question 471 Mark
State Pythagoras theorem and its converse.
Question 481 Mark
$O$ is a point in the exterior of $\triangle A B C$. What symbol ' > ', ' < ' or ' $=$ ' will you use to complete the statement $O A+O B$.. $A B$ ? Write two other similar statements and show that
$O A+O B+O C>\frac{1}{2}(A B+B C+C A)$
View full question & answer→