Question

The radius of a circle measures 20 centimeters. What is the length of its diameter?

5 cm
10 cm
20 cm
40 cm

Answer 1

\[
diameter = 2\times radius
\]

Answer 2

They are asking you to multiply.

Answer 3

d. The diameter is double the radius, where the radius is the distance from the center of the circle to the circumference. The radius is 20, so the diameter is40.

Answer 4

\[
diameter = radius + radius
\]

Answer 5

Or maybe they are asking you to add.

Answer 6

OK. Thank you.