To find the distance around a circular disc, multiply the diameter of the disc by 3.14. What is the distance around the disc when
(a) the diameter is 18.7 cm
(b) the radius is 6.45 cm

Solution:

a. Diameter of the disc = 18.7 cm

The distance around the disc = 3.14 × 18.7 cm = 58.718 cm

b. Radius of the disc = 6.45 cm

The diameter of the disc = 2 × 6.45 cm = 12.9 cm

Now, the distance around the disc = 3.14 × 12.9 cm = 40.506 cm

✦ Try This: To find the distance around a circular disc, multiply the diameter of the disc by 3.14. What is the distance around the disc when: (a) the diameter is 19.87 cm? (b) the radius is 4.57 cm

To solve the above problem you can follow the fractions and decimals rules to get the required answer.

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 2

NCERT Exemplar Class 7 Maths Chapter 2 Exercise Problem 71

To find the distance around a circular disc, multiply the diameter of the disc by 3.14. What is the distance around the disc when: (a) the diameter is 18.7 cm (b) the radius is 6.45 cm

Summary:

If the diameter is 18.7 cm the distance around the disc is 58.718 cm. If the radius is 6.45 cm the distance around the disc is 40.506 cm

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