Question

What is the circumference of the semicircle?

Answer 1

we know the circumference of circle which

2pir

then circumference of semi circle is

2pir×1/2

where 2 and 2 get cancel

and we are left with pir

so.. pi4

=12.56

Answer 2

`12.56m`

4th answer is correct.

Explanation:

`(180)/(360) * 2\pi \: r \\ (1)/(2) * 2 * \pi * 4 \\ = 12.56m`