Question

What is the diameter of cricle, if the area of cricle is 78.5cm square?

Answer 1

Answer:

10cm

Explanation:

Formula for area of circle = πr^2

78.5 = πr^2

78.5 = 3.14 × r^2

r^2 = 78.5/3.14

= 25

r = √25 = 5cm

Diameter = 2 x radius

= 2 × 5

= 10cm

Answer 2

Explanation:

area of circle = πr^2

so,

πr^2 = 78.5

r^2 = 78.5×7/22

r^2 = 24.977

.r is approximately 5 cm

diameter is twice the radius so,

diameter = 5× 2 = 10 cm