Answer:
6.28
Explanation:
Hi there
to understand this 
you need to know about
- algebra
 - circle
 - area of semi-circle=½×πr²
 
it says to figure out the area of semi-circle not full circle
so
using the formula of area of semi-circle
=½πr²
=½×3.14 × 2²
=2×3.14
=6.28