Question

Bryce is cutting tree trunks into circular pieces of wood 1 inch thick to make wall art for log cabins. Match the circumferences of each wood circle to its diameter or radius.

Answer 1

The circumference of a circle of radius r can be calculated as:

$C=2\pi r$

If the diameter d is given, then the formula is:

$C=\pi d$

Calculate the circumference of the following circles:

1 d = 8 inches.

$\begin{gathered} C=\pi(8\text{ inches}) \\ C=3.14\cdot8\text{ inches} \\ C=25.12\text{ inches} \end{gathered}$

1 matches with b

2 d = 7 inches

$\begin{gathered} C=\pi(7\text{ inches}) \\ C=3.14\cdot7\text{ inches} \\ C=21.98\text{ inches} \end{gathered}$

2 matches with d

3 r = 2 inches

$\begin{gathered} C=2\pi(2\text{ inches\rparen=4}\cdot3.14\text{ inches} \\ C=12.56\text{ inches} \end{gathered}$

3 matches with a

4 r = 3 inches

$\begin{gathered} C=2\pi(3\text{ inches\rparen=6}\cdot3.14\text{ inches} \\ C=18.84\text{ inches} \end{gathered}$

4 matches with c