NCERT Solutions for Class 6 Mathematics Chapter 5 Understanding Elementary Shapes Exercise 5.4 ~ evidya

Exercise 5.4

Ex-5.1
Ex-5.2
Ex-5.3
Ex-5.4
Ex-5.5
Ex-5.6
Ex-5.7
Ex-5.8
Ex-5.9

Q 1 - Ex 5.4 - Understanding Elementary Shape - NCERT Maths Class 6th - Chapter 5

Page No 97:

Question 1:

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

Answer:

(i) The measure of a right angle is 90°.
(ii) The measure of a straight angle is 180°.

Q 2 - Ex 5.4 - Understanding Elementary Shape - NCERT Maths Class 6th - Chapter 5

Question 2:

Say True or False:
(a) The measure of an acute angle < 90°
(b) The measure of an obtuse angle < 90°
(c) The measure of a reflex angle > 180°
(d) The measure of one complete revolution = 360°
(e) If m∠A = 53° and m∠B = 35°, then m∠A > m∠B.

Answer:

(a) True
The measure of an acute angle is less than 90°.
(b) False
The measure of an obtuse angle is greater than 90º but less than 180º.
(c) True
The measure of a reflex angle is greater than 180°.
(d) True
The measure of one complete revolution is 360º.
(e) True

Q 3 - Ex 5.4 - Understanding Elementary Shape - NCERT Maths Class 6th - Chapter 5

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°, 70°
(b) 105°, 132°

Question 4:

Measure the angles given below using the Protractor and write down the measure.

Answer:

(a) 45º
(b) 120º
(c) 90º
(d) 60º, 90º, and 130º

Q 5 - Ex 5.4 - Understanding Elementary Shape - NCERT Maths Class 6th - Chapter 5

Page No 98:

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 = 40º
Measure of angle B = 68º
∠B has the greater measure than ∠A.

Q 6 - Ex 5.4 - Understanding Elementary Shape - NCERT Maths Class 6th - Chapter 5

Question 6:

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

Answer:

The measures of these angles are 45º and 55º. Therefore, the angle shown in 2^nd figure is greater.

Q 7 - Ex 5.4 - Understanding Elementary Shape - NCERT Maths Class 6th - Chapter 5

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 (if the angle is less than 180º)
(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:

The measures of the angles shown in the above figure are 40º, 130º, 65º, 135º respectively.

Q 9 - Ex 5.4 - Understanding Elementary Shape - NCERT Maths Class 6th - Chapter 5

Question 9:

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

Answer:

(a) 90°
(b) 30°
(c) 180°

Page No 99:

Question 10:

Investigate

In the given figure, the angle measures 30°. Look at the same figure through a magnifying glass. Does the angle become larger? Does the size of the angle change?

Answer:

The measure of this angle will not change.

Question 11:

Measure and classify each angle:

Angle	Measure	Type
∠AOB	–	–
∠AOC	–	–
∠BOC	–	–
∠DOC	–	–
∠DOA	–	–
∠DOB	–	–

Answer:

Angle	Measure	Type
∠AOB	40º	Acute
∠AOC	125º	Obtuse
∠BOC	85º	Acute
∠DOC	95º	Obtuse
∠DOA	140º	Obtuse
∠DOB	180º	Straight

Monday, May 25, 2020