Question

1. the diameter of a circle is 19 cm. find its circumference in terms of π. d = 19 c = πd c = 19π cm 2. the radius of a circle is 17 in. find its circumference in terms of π.

Explanation:

Step1: Recall the circumference - diameter formula

The formula for the circumference $C$ of a circle in terms of the diameter $d$ is $C = \pi d$.

Step2: Substitute the given diameter value

Given that $d = 19$ cm, substituting into the formula $C=\pi d$, we get $C = 19\pi$ cm.

for second - part:

Step1: Find the diameter

Since the radius $r = 17$ in, and the diameter $d=2r$, then $d = 2\times17=34$ in.

Step2: Use the circumference - diameter formula

The formula for the circumference $C$ of a circle is $C=\pi d$. Substituting $d = 34$ in, we get $C = 34\pi$ in.

Answer:

$19\pi$ cm