Question

Find the circumference of circle if the area is 300 square centimeters

Answer 1

pi*r^2 = 300

r = √(300/pi)

So circumference = 2*pi*r = 2√(300pi)

Answer 2

Area of circle
πr² = 300 cm²
r = √(300/π)
r = 9.77205 cm
r ≈ 9.77cm (3s.f.)

Circumference of circle
= 2πr
= 2π(9.77205)
= 61.39960
≈ 61.4 cm (3s.f.)