Question

If the radius of a circle is 4.2 cm, compute its area and circumference.​

Answer 1

Area of a circle = πr2

So, area = π(4.2)2 = 55.44 cm2

Circumference of a circle = 2πr

So, circumference = 2π(4.2) = 26.4 cm

Answer 2

Area of circle = pie r^2

= 22/7× 4.2×4.2

= 22×0.6×4.2

= 55.44 cm^2

Circumference of circle = pie × r

= 22/7 × 4.2

= 26.4 cm