Understanding elementary shapes Ex-5.4

NCERT solutions for Maths Understanding elementary 

NCERT Solutions for Class 6 Maths Understanding elementary

Class –VI

Mathematics

(Ex. 5.4)

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

Answer:

(i) ${90^ \circ }$

(ii) ${180^ \circ }$

NCERT Solutions for Class 6 Maths Exercise 5.4

Question 2.Say True or False:

(a)The measure of an acute angle <${90^ \circ }.$

(b)The measure of an obtuse angle <${90^ \circ }.$

(c)The measure of a reflex angle >${180^ \circ }.$

(d)The measure of on complete revolution= ${360^ \circ }.$

(e)If $m\angle$A = $53^\circ$ and $m\angle$B = $35^\circ ,$ then $m\angle$A >$m\angle$B.

Answer: (a) True, (b) False, (c) True, (d) True, (e) True

Question 3.Write down the measure of:

(a) some acute angles (b) some obtuse angles

(give at least two examples of each)

Answer:

(a) $35^\circ ,20^\circ$

(b) $110^\circ ,135^\circ$

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

Answer:

(a) $40^\circ$

(b) $130^\circ$

(c) ${90^ \circ }$

(d) ${60^ \circ }$

NCERT Solutions for Class 6 Maths Exercise 5.4

Question 5.Which angle has a large measure? First estimate and then measure:

Measure of angle A =

Measure of angle B =

Answer: $\angle$B has larger measure.

$\angle$A = $40^\circ$ and $\angle$B = $65^\circ$

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

Answer: Second angle has larger measure.

NCERT Solutions for Class 6 Maths Exercise 5.4

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 ________________.

(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 ________________.

Answer: (a) acute angle, (b) obtuse angle, (c) straight angle, (d) acute angle, (e) 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:

(i)${30^ \circ }$

(ii) ${120^ \circ }$

(iii) ${60^ \circ }$

(iv) ${150^ \circ }$

NCERT Solutions for Class 6 Maths Exercise 5.4

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

Answer:

(i)${90^ \circ }$ (Right angle)

(ii) ${30^ \circ }$ (Acute angle)

(iii) ${180^ \circ }$ (Straight angle)

Question 10.Investigate:

In the given figure, the angle measure ${30^ \circ }.$ Look at the same figure through a magnifying glass. Does the angle becomes larger? Does the size of the angle change?

Answer: No, the measure of angle will be same.

NCERT Solutions for Class 6 Maths Exercise 5.4

Question 11.Measure and classify each angle:

Answer:

Sol.