Idon't understand how to find the area of a circle

You have to find out the radius of the circle so u have to find it in the middle of the circle

Area of a circle is calculated by this expression

A = πR²

What this says is Area is equal to the radius squared times pi (3.14 for all intensive purposes.)

So, we need to find A (area.)

We know the diameter (d) is twice the radius, and we know that the diameter is 10.

10/2 = 5.

The radius is 5.

A = π5²

5² = 5 x 5 = 25

A = π25

3.14 (π) * 25 = 78.5

The area of the circle with the diameter of 10 is 78.5 roughly. This is not exact but for what you are doing it will suffice.