Question

1. the diameter of a circle is 20 m. find its circumference in terms of π. d = 20m c = 2πr r = 19 c = 2π×19 = 38π pl 8. the radius of a circle is 19 ft. find its terms of π.

Explanation:

Step1: Recall the radius - diameter relationship

The radius $r$ of a circle is related to the diameter $d$ by the formula $r=\frac{d}{2}$. Given $d = 20$ m, then $r=\frac{20}{2}=10$ m.

Step2: Use the circumference formula

The formula for the circumference $C$ of a circle is $C = 2\pi r$ or $C=\pi d$. Using $C=\pi d$ (since $d = 20$ m), we get $C = 20\pi$ m. Using $C = 2\pi r$ with $r = 10$ m, we also have $C=2\pi\times10=20\pi$ m.

Answer:

$20\pi$ m