Jim has 20-inch wheels on his bicycle (their diameter is 20 inches). The tires are worn out, and he would like to cut them into pieces to use as a bumper on something he's making. Estimate the length of rubber Jim would get from his two bicycle tires.

Question

anonymous · Answer

The length is the perimeter of a circle, given by:
$$P=2\Pi*r=d*\Pi=20\Pi inches$$
Since there are two, then he will get 20pi*2=40pi inches of rubber.