The radius is 6.5, what is the diameter, circumference, and area?
Diameter is 13 units. Circumference is about 40.82 units. Area is about 132.67 units^2.
The diameter is simply found by multiplying the radius by 2 because a radius is half of the diameter. (6.5 * 2 = 13)
The circumference is equal to a circle's diameter times pi
(about 3.14). So, take the diameter (13) and multiply it by 3.14 to get your circumference, 40.82 units.
The area of a circle is calculated by the formula pi*r^2 (or pi times radius squared). So take the radius (6.5), and multiply it by itself to get 42.25 and then multiply that by pi (3.14) to get the area of the circle, 132.67 units^2.