Question

Perimeter of semicircular plate is 108 cm find area

Answer 1

Answer:

in a semicircular plate, perimeter = semiperimeter + diameter

let d be the diameter

p = pi*d/2 + d

=> 108 = 22/7*d/2 + d

=> 108 = 22d/14 + d

=> 108 = (22d + 14d)/14

=> 108 = (36d)/14

=> 14*108 = 36d

=> d = (108*14)/36

=> d = 42 cm

therefore r = d/2 = 21 cm

Area of semicircular plate = 1/2*pi*r^2

=> A= (22*21*21)/7*2

=> A = 11*3*21

=> A = 63*11

A = 693 sq cm