Question

What is the radius of a circle whose diameter is 13 units?

Answer 1

`13/2` units or `7.5` units

Explanation:

The diameter can expressed with the formula:

`d = 2r`

where:
d = diameter
r = radius

This means that the diameter is double the length of the radius. To find the radius, do:

`d = 2r`
`13 = 2r`
`13/2 = r`

`:.`, the radius is `13/2` units or `7.5` units.