Question

find the radius of each circle. use your calculators value of π. round your answer to the nearest tenth.

1. circumference = 62.8 mi

10 mi

1. circumference = 12.6 yd

2 yd

1. circumference = 69.1 yd

11 yd

1. circumference = 25.1 ft

4 ft

Explanation:

Step1: Recall the circumference formula

The formula for the circumference of a circle is $C = 2\pi r$, where $C$ is the circumference and $r$ is the radius. We can solve for $r$: $r=\frac{C}{2\pi}$.

Step2: Solve for 17)

Given $C = 62.8$ mi. Substitute into the formula: $r=\frac{62.8}{2\pi}$. Using a calculator with $\pi$ value, $r=\frac{62.8}{2\times3.14159}\approx10.0$ mi.

Step3: Solve for 18)

Given $C = 69.1$ yd. Then $r=\frac{69.1}{2\pi}=\frac{69.1}{2\times3.14159}\approx11.0$ yd.

Step4: Solve for 19)

Given $C = 12.6$ yd. So $r=\frac{12.6}{2\pi}=\frac{12.6}{2\times3.14159}\approx2.0$ yd.

Step5: Solve for 20)

Given $C = 25.1$ ft. Then $r=\frac{25.1}{2\pi}=\frac{25.1}{2\times3.14159}\approx4.0$ ft.

Answer:

1. $10.0$ mi
2. $11.0$ yd
3. $2.0$ yd
4. $4.0$ ft