NCERT Solutions Class 6 Maths Chapter 5 Understanding Elementary Shapes Ex 5.4

NCERT Solutions Class 6 Maths
Chapter – 5 (Understanding Elementary Shapes)

The NCERT Solutions in English Language for Class 6 Mathematics Chapter – 5 Understanding Elementary Shapes Exercise 5.4 has been provided here to help the students in solving the questions from this exercise.

Chapter 5: Understanding Elementary Shapes

• NCERT Solution Class 6 Maths Exercise – 5.1
• NCERT Solution Class 6 Maths Exercise – 5.2
• NCERT Solution Class 6 Maths Exercise – 5.3
• NCERT Solution Class 6 Maths Exercise – 5.5
• NCERT Solution Class 6 Maths Exercise – 5.6
• NCERT Solution Class 6 Maths Exercise – 5.7
• NCERT Solution Class 6 Maths Exercise – 5.8
• NCERT Solution Class 6 Maths Exercise – 5.9

Exercise – 5.4

1. What is the measure of
(i) a right angle?
(ii) a straight angle

Solutions:

(i) The measure of a right angle is 90⁰.
(ii) The measure of a straight angle is 180⁰.

2. Say True or False:

(a) The measure of an acute angle < 90⁰.
(b) The measure of an obtuse angle < 90⁰.
(c) The measure of a reflex angle > 180⁰.
(d) The measure of one complete revolution = 360⁰.
(e) If m ∠A = 53⁰ and m ∠B = 35⁰, then m ∠A > m ∠B.

Solutions:

(a) True, the measure of an acute angle is less than 90⁰.
(b) False, the measure of an obtuse angle is more than 90⁰ but less than 180⁰.
(c) True, the measure of a reflex angle is more than 180⁰.
(d) True, the measure of one complete revolution is 360⁰.
(e) True, ∠A is greater than ∠B.

3. Write down the measures of
(a) some acute angles
(b) some obtuse angles
(give at least two examples of each)

Solutions:

(a) The measures of an acute angle are 60⁰, 70⁰.
(b) The measures of obtuse angle are 120⁰, 150⁰.

4. Measures the angles given below using the protractor and write down the measure.

Solutions:

(a) The measure of an angle is 45⁰
(b) The measure of an angle is 120⁰
(c) The measure of an angle is 90⁰
(d) The measures of an angles are 60⁰, 90⁰ and 130⁰

5. Which angle has a large measure? First estimate and then measure.
Measure of Angle A =
Measure of Angle B =

Solutions:

The measure of angle A is 40⁰
The measure of angle B is 68⁰
∠B has a large measure than ∠A

6. From these two angles which has larger measure? Estimate and then confirm by measuring them.

Solutions:

The measures of these angles are 45⁰ and 55⁰. Hence, angle shown in second figure is greater.

7. Fill in the blanks with acute, obtuse, right or straight:

(a) An angle whose measure is less than that of a right angle is _____.
(b) An angle whose measure is greater than that of a right angle is ____.
(c) An angle whose measure is the sum of the measures of two right angles is _______.
(d) When the sum of the measures of two angles is that of a right angle, then each one of them is _____.
(e) When the sum of the measures of two angles is that of a straight angle and if one of them is acute then the other should be ______.

Solutions:

(a)An angle whose measure is less than that of a right angle is acute angle.
(b) An angle whose measure is greater than that of a right angle is obtuse angle (but less than 180⁰).
(c) An angle whose measure is the sum of the measures of two right angles is straight angle.
(d) When the sum of the measures of two angles is that of a right angle, then each one of them is acute angle.
(e) When the sum of the measures of two angles is that of a straight angle and if one of them is acute then the other should be obtuse angle.

8. Find the measure of the angle shown in each figure. (First estimate with your eyes and then find the actual measure with a protractor).

Solutions:

The measures of the angles shown in above figure are 40⁰, 130⁰, 65⁰ and 135⁰.

9. Find the angle measure between the hands of the clock in each figure:
Solutions:

The angle measure between the hands of the clock are 90⁰, 30⁰ and 180⁰

10. Investigate :
In the given figure, the angle measure 30⁰. Look at the same figure through a magnifying glass. Does the angle becomes larger? Does the size of the angle change?

Solutions:

The measure of an angle will not change by viewing through a magnifying glass

11. Measure and classify each angle:

Solutions: