Question

If the perimetre of a semi circular protactor is 108 cm then qhat will be the daimetre of it

Answer 1

Answer: 42cm.

Step-by-step explanation: Perimeter of a semicircle = diameter + (circumference/2)

Or, 2r + πr = 108cm where r is the radius.

So, r ( 2 + π) = 108cm.

=) r = 108 * 7 / 14 + 22 (as pi = approximately 22/7 and 2 + pi = 14 + 22/7)

Thus, r = 108 * 7 / 36

= 21cm.

Thus, the diameter (2r) = 42cm.