What is the formula for finding area of a semi circle?

The formula for finding the area of a full circle is πr2, I believe, where "r" represents the radius of the circle. Since you're finding the area of a semi-circle, you'll be looking for half of the area of a circle, which means you have to use the formula for finding the area of a semi-circle and then divide it by two.

I'm not a 100% sure here. But I believe.

Formula for the area of a circle 2

A = pi r