Question

A circle has a diameter with endpoints at (0, 4) and (0, –8). What is the approximate area of the circle?

Answer 1

`36\pi`

Explanation:

The diameter is:

The Euclidean distance between points (x1, y1) and (x2, y2) is:

sqrt((x1 - x2)^2 + (y1 - y2)^2)

Substitute (x1, y1) = (0, 4) and (x2, y2) = (0, -8):

= sqrt((-0 + 0)^2 + (-(-8) + 4)^2)

= sqrt(12^2)

= 12

or simply:

diameter: 4-(-8)=12

The radius is:

12/2=6 units

The area of the circle:

`\pi r^2=\pi(6^2)=36\pi`

Answer 2

113.04

Explanation:

Area of a circle is πr2

π = 3.14

r = 6

πr2 = 113.04