Question

What is the area of a semicircle with diameter of 6

Answer 1

Your answer is 14.13.
Heres how I got it:
First, the formula for area of a semi circle is 3.14 x r^2 and divide by two.
To find the radius, we need to divide the diameter by two, which is 3.
Now, lets plug in our numbers. 
3.14 x 3^2/2
3.14 x 9/2
28.26/2
A=14.13

Answer 2

Area of circle = pi (d/2)^2
area of semi-circle =0.5* pi (d/2)^2
                             =0.5* pi (6/2)^2
                             =14.14