Math Problem Solver

The circumference of a circle is $15 \pi \approx 47.12\, \text{cm}$.

Note: Approximate solutions are rounded to the nearest hundredths place.

Given: $$\begin{aligned}d&=15\end{aligned}$$

Circumference

The circumference of a circle is given by the equation: $$\begin{aligned}C&=2 \pi r\end{aligned}$$ where $C$ is circumference and $r$ is radius.

Need:$$\begin{aligned}d&=2 r\end{aligned} \quad \Rightarrow \quad \begin{aligned}15&=2 r\end{aligned} \quad \Rightarrow \quad \begin{aligned}r&=\frac{15}{2} = 7.5\end{aligned}$$

Solution:$$\begin{aligned}C&=2 \pi r\\C&=2 \pi \left(\frac{15}{2}\right)\\C&=15 \pi\end{aligned}$$

A circle is a two dimensional figure that has no corners or edges. Its radius r is the distance between the center of the circle and any point on the circle. Its diameter d is twice the radius, forming a line segment passing through the center of the circle.

The circumference C, also known as perimeter P, of a circle is the distance around a circle. $$\begin{aligned} C &= 2 \pi r \\ &= \pi d \end{aligned}$$

The area A of a circle is the region enclosed inside it. $$A = \pi r^{2}$$