Question

The diameter of a circle is 5 centimeters. What is the circumference?Give the exact answer in simplest form._____ centimeters (pi, fraction)

Answer 1

5π cm

1) Since the Diameter is 5 cm and the diameter of a circle is twice the radius, then the radius is 2.5 cm

$\begin{gathered} D=2R \\ 5=2R \\ R=\frac{5}{2}\text{ or 2.5} \end{gathered}$

2) To find out the Circumference, we must plug into that the radius measure.

$\begin{gathered} C=2\pi R \\ C=2\pi\cdot\frac{5}{2} \\ C=5\pi \end{gathered}$

3) Hence, the Circumference (Perimeter) is 5π cm