Question

15. A piece of wire of length 108 cm is bent to form a semicircular arc bounded by its
diameter. Find the radius and the area enclosed.​

Answer 1

Step-by-step explanation:

length of wire= 108 cm

it is bent into semicircle

1/2 × 2 pie r

pie r

Answer 2

Length of wire = 108 cm

Let r be the radius of the semicircle

πr+ 2r = 108

⇒ r(π + 2) = 108 ⇒ r = ((22/7) + 2) =  108

⇒ (36/7)r = 108  ⇒ r = (108 × 7)/36 = 27 cm

Area = πr2 /2 = (22/(7 × 2)) × 21 × 21 = (1386/2) cm2

= 693 cm2