Question

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?

Answer 1

(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

∴ Diameter of the disc = 2 × 6.45 cm = 12.9 cm

∴ The distance around the disc

= 3.14 × 12.9 cm = 40.506 cm