Question

How do you determine the area of a circle? Could you give an example please?

Answer 1

To determine the area if the circle, you must know the diameter or the radius of a circle.

If you know the radius of a circle, use this as your formula. Remember: Pi (the greek symbol thingy) is equal to 3.1415. (A is equal to area of the circle and r represents the radius)
$a = \pi {r}^{2}$
If you know the diameter, just divide the diameter to get the radius then use the same equation.

Answer 2

3.14*r^2

R stands for radius.

So if you are given that the diameter of a circle is 10 feet, we know the radius is half the diameter. So the radius is 5. So the equation is going to be 3.14*5^2 so the area would be about 78.54 feet