Question

1. the radius of a circle is 7 m. find its c terms of π. c = 2πr c = 2π(7) c = 14π
2. the circumference of a circle is 20π c diameter, in centimeters.
3. the diameter of a circle is 20 m. find circumference in terms of π. d = 20m c = 2πr r = 19 c = 2×19 = 38π

Explanation:

Step1: Recall the formula for circumference

The formula for the circumference of a circle is $C = 2\pi r$ or $C=\pi d$, where $r$ is the radius and $d$ is the diameter.

Step2: Solve problem 6

Given $C = 20\pi$ cm. Since $C=\pi d$, then $d=\frac{C}{\pi}$. Substituting $C = 20\pi$ into the formula, we get $d = 20$ cm.

Step3: Solve problem 7

Given $d = 20$ m. Since $C=\pi d$, substituting $d = 20$ into the formula, we have $C = 20\pi$ m.

Answer:

1. 20 cm
2. $20\pi$ m