Question 11 Mark
The Ashoka Chakra has 24 spokes. What is the degree measure of the angle between two spokes next to each other? What is the largest acute angle formed between two spokes?
Questions
1 Marks Question
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24 questions · self-marked practice — reveal the answer and mark yourself.
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Question 21 Mark
Draw the letter ' $Y$ ' such that the three angles formed are $150^{\circ}, 60^{\circ}$ and $150^{\circ}$.
View full question & answer→Question 31 Mark
Draw the letter ' $M$ 'such that the angles on the sides are $40^{\circ}$ each and the angle in the middle is $60^{\circ}$.
View full question & answer→Question 41 Mark
Make any figure with three acute angles, one right angle and two obtuse angles.
Question 51 Mark
Draw an angle whose degree measure is the same as the angle given below:
Also, write down the steps you followed to draw the angle.
Also, write down the steps you followed to draw the angle.
Answer
View full question & answer→Step 1. Measure the given angle $\left(\angle IHJ =120^{\circ}\right)$
Step 2. Using a protractor draw $\angle A B C=120^{\circ}$
Step 2. Using a protractor draw $\angle A B C=120^{\circ}$
Question 61 Mark
Observe the images below where there is an insect and its rotated version, fan angles be used to describe the amount of rotation? How? What will be the arms of the angle and the vertex?
Hint: Observe the horizontal line touching the insects.
Hint: Observe the horizontal line touching the insects.
Answer
View full question & answer→Both insects are rotated $90^{\circ}$ clockwise.
Question 71 Mark
Vidya is enjoying her time on the swing. She notices that the greater the angle with which she starts the swinging, the greater is the speed she achieves on her swing. But where is the angle? Are you able to see any angle?
Answer
View full question & answer→Yes, an angle can be seen.
Question 81 Mark
Find the degree measures for the angles given below. Check if your paper protractor can be used here!
Answer
View full question & answer→In first figure, we get $\angle I H J=45^{\circ}$
In second figure, we get $\angle I H J=115^{\circ}$
Explanation To accurately measure these angles, insure your paper protractor is precise and that it can measure the angles in given figure.
In second figure, we get $\angle I H J=115^{\circ}$
Explanation To accurately measure these angles, insure your paper protractor is precise and that it can measure the angles in given figure.
Question 91 Mark
Answer
View full question & answer→(a) The number of units of 1 degree angle between $K A$ and $A L$ is 30.
$\therefore \angle K A L=30^{\circ}$
(b) The number of units of 1 degree angle between $L A$ and $A W$ is 50.
$\therefore \angle W A L=50^{\circ}$
(c) The number of units of 1 degree angle between $K A$ and $A T$ is 120.
$\therefore \angle T A K=120^{\circ}$
$\therefore \angle K A L=30^{\circ}$
(b) The number of units of 1 degree angle between $L A$ and $A W$ is 50.
$\therefore \angle W A L=50^{\circ}$
(c) The number of units of 1 degree angle between $K A$ and $A T$ is 120.
$\therefore \angle T A K=120^{\circ}$
Question 101 Mark
Answer
View full question & answer→(a) For triangle (a), on measuring angles $\angle A, \angle B$ and $\angle C$ using protractor, we get
$\angle A=45^{\circ}, \angle B=65^{\circ}$ and $\angle C=70^{\circ}$
On adding all the three angles, we get
$45^{\circ}+65^{\circ}+70^{\circ}=180^{\circ}$
(b) For triangle (b), on measuring angles $\angle A, \angle B$ and $\angle C$ using protractor, we get $\angle A=60^{\circ}, \angle B=60^{\circ}$ and $\angle C=60^{\circ}$
On adding all the angles, we get
$60^{\circ}+60^{\circ}+60^{\circ}=180^{\circ}$
(c) For triangle (c), using protractor, we get $\angle A=35^{\circ}, \angle B=55^{\circ}$ and $\angle C=90^{\circ}$
On adding all the angles, we get
$35^{\circ}+55^{\circ}+90^{\circ}=180^{\circ}$
Now, we can say that the sum of all the angles of a triangle is $180^{\circ}$.
$\angle A=45^{\circ}, \angle B=65^{\circ}$ and $\angle C=70^{\circ}$
On adding all the three angles, we get
$45^{\circ}+65^{\circ}+70^{\circ}=180^{\circ}$
(b) For triangle (b), on measuring angles $\angle A, \angle B$ and $\angle C$ using protractor, we get $\angle A=60^{\circ}, \angle B=60^{\circ}$ and $\angle C=60^{\circ}$
On adding all the angles, we get
$60^{\circ}+60^{\circ}+60^{\circ}=180^{\circ}$
(c) For triangle (c), using protractor, we get $\angle A=35^{\circ}, \angle B=55^{\circ}$ and $\angle C=90^{\circ}$
On adding all the angles, we get
$35^{\circ}+55^{\circ}+90^{\circ}=180^{\circ}$
Now, we can say that the sum of all the angles of a triangle is $180^{\circ}$.
Question 111 Mark
Do you know what the words acute and obtuse mean? Acute means sharp and obtuse means blunt. Why do you think these words have been chosen?
Answer
View full question & answer→The word 'acute and obtuse' are used to describe angles because they reflect the visual characteristics of the angle.
• Acute angles are called sharp because they are less than 90° and appear pointed, similar to the sharp edge of a knife.
• Obtuse angles are called 'blunt' because they are greater than 90° and appear wider, similar to the blunt end of an object.
Explanation These words help to visualise the nature of the angles where an acute angle looks more pointed and an obtuse angle looks wider and less pointed.
• Acute angles are called sharp because they are less than 90° and appear pointed, similar to the sharp edge of a knife.
• Obtuse angles are called 'blunt' because they are greater than 90° and appear wider, similar to the blunt end of an object.
Explanation These words help to visualise the nature of the angles where an acute angle looks more pointed and an obtuse angle looks wider and less pointed.
Question 121 Mark
Make a few acute angles and a few obtuse angles. Draw them in different orientations.
Question 131 Mark
Answer
View full question & answer→In the first group, all the angles are less than a right angle. So, these are acute angles.
In the second group, all the angles are right angles. In the third group, all the angles are more than a right angle. So, these are obtuse angles.
In the second group, all the angles are right angles. In the third group, all the angles are more than a right angle. So, these are obtuse angles.
Question 141 Mark
Join A to other grid points in the figure by a straight line to get a straight angle. What are all the different ways of doing it?
Question 151 Mark
Find the degree measures of $\angle P Q R, \angle P Q S$ and $\angle P Q T$.
Answer
View full question & answer→In the given figure, on measuring each angle by placing the protractor at the vertex Q and reading the angles formed by the rays, we get
$\angle PQR =45^{\circ}$, $\angle P Q S=80^{\circ}$ and $\angle PQT =150^{\circ}$
$\angle PQR =45^{\circ}$, $\angle P Q S=80^{\circ}$ and $\angle PQT =150^{\circ}$
Question 161 Mark
Here is a ray $\overrightarrow{ OA }$ in given figure. It starts at O and passes through the point A. It also passes through the point B.
(a) Can you also name it as $\overrightarrow{ OB }$ ? Why ?
(b) Can we write $\overrightarrow{ OA }$ as $\overrightarrow{ AO }$ ? Why or why not ?
(a) Can you also name it as $\overrightarrow{ OB }$ ? Why ?
(b) Can we write $\overrightarrow{ OA }$ as $\overrightarrow{ AO }$ ? Why or why not ?
Answer
View full question & answer→(a) Yes, we can also name of ray $\overrightarrow{O A}$ as ray $\overrightarrow{O B}$ because initial point of both is same and going on endlessly in the same direction.
(b) No, we cannot not write $\overrightarrow{O A}$ as $\overrightarrow{A O}$ because initial point of a ray cannot be changed.
(b) No, we cannot not write $\overrightarrow{O A}$ as $\overrightarrow{A O}$ because initial point of a ray cannot be changed.
Question 171 Mark
Answer
View full question & answer→(a) Five points are D, E, O, C and B.
(b) In the given figure, a line is $\stackrel{\leftrightarrow}{D B}$.
(c) Four rays are $\overrightarrow{O C}, \overrightarrow{O B}, \overrightarrow{E B}$ and $\overrightarrow{O D}$.
(d) Five line segments are $\overline{D E}, \overline{E O}, \overline{O B}, \overline{D O}$ and $\overline{E B}$.
(b) In the given figure, a line is $\stackrel{\leftrightarrow}{D B}$.
(c) Four rays are $\overrightarrow{O C}, \overrightarrow{O B}, \overrightarrow{E B}$ and $\overrightarrow{O D}$.
(d) Five line segments are $\overline{D E}, \overline{E O}, \overline{O B}, \overline{D O}$ and $\overline{E B}$.
Question 181 Mark
Draw a rough figure and write labels appropriately to illustrate each of the following:
(a) $\overleftrightarrow{O P}$ and $\overleftrightarrow{O Q}$ meet at 0.
(b) $\overrightarrow{X Y}$ and $\stackrel{\leftrightarrow}{PQ}$ intersect at point $M$.
(c) Line L contains points E and F but not point D.
(d) Point P lies on AB.
(a) $\overleftrightarrow{O P}$ and $\overleftrightarrow{O Q}$ meet at 0.
(b) $\overrightarrow{X Y}$ and $\stackrel{\leftrightarrow}{PQ}$ intersect at point $M$.
(c) Line L contains points E and F but not point D.
(d) Point P lies on AB.
Answer
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Question 191 Mark
Answer
View full question & answer→Rays in the given figure are $\overrightarrow{T A}, \overrightarrow{T N}$ and $\overrightarrow{T B}$.
Yes, $T$ is the starting point of each of these rays in given figure.
Yes, $T$ is the starting point of each of these rays in given figure.
Question 201 Mark
Answer
View full question & answer→The line segments in the given figure are $\overline{L M}, \overline{M P}, \overline{P Q}$ and $\overline{Q R}$ Points $L$ and $R$ are on exactly one of the line segments and points $M, P$ and $Q$ are on two of the line segments.
Question 211 Mark
Rihan marked a point on a piece of paper.
How many lines can he draw that pass through the point. Sheetal marked two points on a plece of paper. How many different lines can she draw that pass through both of the points?
Can you help Rihan and Sheetal, find their answers?
How many lines can he draw that pass through the point. Sheetal marked two points on a plece of paper. How many different lines can she draw that pass through both of the points?
Can you help Rihan and Sheetal, find their answers?
Answer
View full question & answer→Yes, Rihan can draw infinite lines passing through a point and Sheetal can draw only one line passing through both of the points.
Question 221 Mark
Make the paper craft as per the given instructions. Then, unfold and open the paper fully. Draw lines on the creases made and measure the angles formed.
Answer
View full question & answer→self
Question 231 Mark
Find the degree measures of different angles in your classroom using your protractor. .
Answer
View full question & answer→Angle at comer of blackboard $=90^{\circ}$
Angle at comer of desk $=90^{\circ}$
Angle at comer of desk $=90^{\circ}$
Question 241 Mark
Find the degree measures of the following angles using your protractor.
Answer
View full question & answer→On measuring above angles by a protractor, we get
$\angle IHJ =48^{\circ}$
$\angle GHK=25^{\circ}$
and $\angle IHK =110^{\circ}$
$\angle IHJ =48^{\circ}$
$\angle GHK=25^{\circ}$
and $\angle IHK =110^{\circ}$