Question

One of the diameters of a circle has the endpoints (-2, 3) and (-2, -2). What is the radius of this circle?

Answer 1

Use the distance formula to find the diameter:

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

Diameter = sqrt((-2 - -2)^2 + (-2 - 3)^2)

Diameter = sqrt((0)^2 + -5^2)

Diameter = sqrt(5^2)

Diameter = 5

The radius is half the diameter: 5/2 =  2.5 units