Question

the perimeter of a semicircle is 396 cm then its diameter
(in cm) is?​

Answer 1

Answer- The above question is from the chapter 'Areas Related to Circles'.

Concept used: 1) Perimeter of semicircle = 2r + πr

2) 2r = d (Diameter)

Given question: The perimeter of a semicircle is 396 cm, then its diameter

(in cm) is ________ .

Answer: Perimeter of semicircle = 396 cm​

2r + πr = 396

r(2 + π) = 396

r = $\frac{396}{2 \: + \: \pi}$

r = $\frac{396 \: * \: 7}{14 \: + \: 22}$

r = $\frac{396 \: * 7}{36}$

r = 11 × 7

r = 77 cm

2r = d

d = 77 × 2

d = 154 cm

∴ Diameter of circle = 154 cm