Question

If perimeter of semicircle is 72cm then find radius of the circle.​

Answer 1

Answer:

Radius of circle = 14 cm

Step-by-step explanation:

Given : Perimeter of semicircle = 72 cm

Let the radius of the circle be denoted by r.

According to the figure (see attachment),

Perimeter of semicircle = Circumference of semicircle + Diameter

• Circumference of semicircle = Circumference of circle / 2

= (2πr) / 2 = πr

• Diameter = 2 × Radius of circle

= 2r

∴ πr + 2r = 72

On solving further, we get

→ r(π + 2) = 72

Taking π = 22/7

→ r(22/7 + 2) = 72

→ r(36/7) = 72

→ r = (72 × 7) / 36

→ r = 14 cm