Q1Written answer
What is the measure of
(i) a right angle
(ii) a straight angle
Show solutionHide solution
Worked solution
(i) The measure of a right angle is 900
(ii) The measure of a straight angle is 1800
NCERT · Class 6 · Maths
Chapter 5: Understanding Elementary Shapes
Practice each question, then open the answer or worked solution.
Exercise 5.4
Textbook page 97 · 11 questionsQ2Written answer
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.
Show solutionHide solution
Worked solution
(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
Q3Written answer
Write down the measures of
(a) some acute angles
(b) some obtuse angles
(give at least two examples of each)
Show solutionHide solution
Worked solution
(a) The measures of an acute angle are 500, 650
(b) The measures of obtuse angle are 1100, 1750
Q4Written answer
Measures the angles given below using the protractor and write down the measure.
Show solutionHide solution
Worked solution
(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
Q5Written answer
Which angle has a large measure? First estimate and then measure.
Measure of Angle A =
Measure of Angle B =
Show solutionHide solution
Worked solution
The measure of angle A is 400
The measure of angle B is 680
∠B has a large measure than ∠A
Q6Written answer
From these two angles which has larger measure? Estimate and then confirm by measuring them.
Show solutionHide solution
Worked solution
The measures of these angles are 450 and 550. Hence, angle shown in second figure is greater.
Q7Written answer
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 ______
Show solutionHide solution
Worked solution
(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.
Q8Written answer
Find the measure of the angle shown in each figure. (First estimate with your eyes and then find the actual measure with a protractor).
Show solutionHide solution
Worked solution
The measures of the angles shown in above figure are 400, 1300, 650 and 1350
Q9Written answer
Find the angle measure between the hands of the clock in each figure:
Show solutionHide solution
Worked solution
The angle measure between the hands of the clock are 900, 300 and 1800
Q10Written answer
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?
Show solutionHide solution
Worked solution
The measure of an angle will not change by viewing through a magnifying glass