Question

The perimeter of a semi circle is 5.14 km. What is the semi circles diameter.

Answer 1

Diameter of semicircle is equal to 2 km.

Explanation:

Given: Perimeter of semicircle = P = 5.14 km

d=?

Perimeter of semicircle is given by

$P = (\pi \times r ) + d\\5.14 = (\pi \times r ) + d\\\\Since \ d=2r; \ r=\frac{d}{2} \\5.14 = (\pi \times \frac{d}{2}) + d$

Simplifying the above equation

$5.14 = ( \frac{(\pi \times d) + 2d}{2}) \\\\5.14 \times 2 = d(\pi +2)\\\\d=\frac{5.14 \times 2}{\pi +2 }$

As value of pi = 3.14, equation becomes

$d=\frac{5.14 \times 2}{\ 3.14 +2} = \frac{10.28}{5.14} =2 \ km$

Diameter of semicircle is equal to 2 km.