Question

if the perimeter of a semi circular protactor is 36cm then its diameter is??

Answer 1

Hey MATE!

Semi perimeter of a semi circle is given by :

SC = πr + r

36 = r (π + 1)

r = 36/(π + 1) cm.


Hope it helps

Hakuna Matata :))

Answer 2

Given,perimeter of semi circular protactor = 36 cm
_______________________________
since , we know that ,
_______________________________
perimeter of semicircle = πr + 2 r
_______________________________
_______________________________
according to question:
_______________________________

π r + 2 r = 36 cm

r ( π + 2 ) = 36 cm

r = 36 / ( π + 2 )

r = 36 / ( 22 / 7 + 2 )

r = 36 × 7 / 36

r = 7 cm

______________________________
diameter of semicircle = 2 r
______________________________

= 2 × 7 = 14 cm

therefore ,

diameter of semicircular protactor
= 14 cm

_______________________________
Your Answer : D = 14 cm
_______________________________