RBSE Solutions for Class 6 Maths Chapter 5 Understanding Elementary Shapes Ex 5.4

Rajasthan Board RBSE Solutions for Class 6 Maths Chapter 5 Understanding Elementary Shapes Ex 5.4 Textbook Exercise Questions and Answers.

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

Question 1.
What is the measure of:
(i) a right angle?
Answer:
The measure of a right angle is 90°.

(ii) a straight angle?
Answer:
The measure of a straight angle is 180°.

Question 2.
Say True or False :
(a) The measure of an acute angle < 90.
Answer:
True. The measure of an acute angle is less than 90°.

(b) The measure of an obtuse angle < 90°.
Answer:
False. The measure of an obtuse angle is greater than 90° but less than 180°.

(c) The measure of a reflex angle > 180°.
Answer:
True. The measure of a reflex angle is greater than 180°.

(d) The measure of one complete revolution = 360°.
Answer:
True. The measure of one complete revolution is 360°.

(e) If m∠A = 53° and m∠B = 35°, then m∠A > m∠B.
Answer:
True. The measure of angle A is greater than measure of angle B.

Question 3.
Write down the measures of:
(a) some acute angles.
(b) some obtuse angles.
(Give at least two examples of each.)
Answer:
(a) 45°, 35°, 72", 20°
(b) 110°, 135°, 105°, 140°

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

Answer:
(a) 45°
(b) 125°
(c) 90°
(d) 60°, 90°, 125°

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

Measure of angle B =

Answer:
Measure of angle A = 40°
Measure of angle B = 65°
∠B has greater measure than ∠A.

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

Answer:
The measure of the angles are 45° and 55°.
Therefore, the angle shown in 2nd figure is larger.

Question 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 ______
Answer:
acute angle

(b) An angle whose measure is greater than that of a right angle is ______
Answer:
obtuse angle

(c) An angle whose measure is the sum of the measures of two right angles is ______
Answer:
straight angle

(d) When the sum of the measures of two angles is that of a right angle, then each one of them is ______
Answer:
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 ______
Answer:
obtuse angle.

Question 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.)

Answer:

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

Answer:
(a) 90° (right angle)
(b) 30° (acute angle)
(c) 180° (straight angle)

Question 10.
Investigate in the given figure, the angle measures 30°. Look at the same figure through a magnifying glass. Does the angle becomes larger? Does the size of the angle change?

Answer:
No, the angle will not become larger. No, the measure of this angle will not change.

Question 11.
Measure and classify each angle :

Answer: