Pizza estimate the area of the top of a round pizza that has a diameter of 16inches. round to the nearest tenth.

So, we're finding the area of a circle. 
The formula for the area of a circle is: 3.14r^2.
So, take the radius, half of the diameter, 8, and square it.
8^2 = 64.
Then, take 64, and multiply it by 3.14, or simplified pi.
64 x 3.14 = 200.96
The answer is 201 inches.

The formula for finding the area of a circle is A = pi X radius squared

To find the radius you have to half the diameter (16 divided by 2 = 8)

Then you can square the radius (8 squared = 64)

Now you can substitute in this would be: area = pi X 64
If you use a calculator (as pi is an irrational number) the answer to one tenth would be 201.1 (201.06)
If you use simplified pi (3.14) the answer to one decimal place would be 201.0 (200.96)