Question

Which is the area of a circle with a diameter of 7 units?

Answer 1

The area of the circle is `(49pi)/4`

Explanation:

The diameter of a circle is the length of a chord passing through the center of the circle, and thus is twice the length of the radius of the circle (the distance from the center to the edge).

The area `A` of a circle with radius `r` is given by `A = pir^2`

So, a circle with diameter `7` has radius `7/2` and thus area
`pi(7/2)^2 = (49pi)/4`