What is the area of a semi circles with the diameter 20

The area of circle can be found using the formula πr² and since we know that semi circle is half the circle so its formula will be 1/2πr².

First we will find the radius.

20/2 = 10

Radius is 10.

A = 1/2(3.14)(10)²
A = 157

Hope this helps :)

If i think this is what your asking, he should look at the grams or pounds/ounces and compare the to their cost then max can identify which one is proportional and which is not ( i think xd)