In the case of a circle, the formula for area, A, is A = pi * r^2, where r is the circle's radius. Since we know that a semicircle is half of a circle, we can simply divide that equation by two to calculate the area of a semicircle. So, the formula for the area of a semicircle is A = pi * r^2/2
B over 2 when u complete the square the only thing you do is find a,b,c when you find b you have to divide it by 2 then square root it.
#5 .
<1= 85
<2= 95
<3= 85
<4= 95
#7=
<1= 154
<2= 26
<3= 154
<4= 26
