Question

find the perimeter of a semicircular plate of radios 3.85 CM.

Answer 1

Hi ,


Let 'r ' is the radius of the semicircle,

Perimeter = π r + 2r

P = r ( π + 2 )

= r ( 22/7 + 2 )

= r ( 22 + 14 ) / 7

P = 36r/7

= ( 36/7 ) × 3.85

[ r = 3.85 given ]

= 36 × 0.55

= 19.80 cm

I hope this helps you.

: )

Answer 2

R = 3.85 cm

perimeter of circle
= the length of the curve of semi circle = 2 π R / 2 = πr = 12.095 cm.

.............

perimeter of semicircle
=> length of curve semicircle + diameter

.......

=> 12.095+2(3.85)= 12.095+7.7
=> 19.80cm