## Elementary Geometry for College Students (6th Edition)

C = 62.8 cm A = 314 $cm^{2}$
Given the diameter of the circle = 20 cm As we know radius of the circle = $\frac{d}{2}$ = $\frac{20}{2}$= 10 cm The circumference of the circle is given by the formula c= $\pi$ d = 2$\pi$ r =2 * 3.14 * 10 = 62.8 cm The area A of a circle whose radius has length r is given by A = $\pi r^{2}$cm = 3.14 * $10^{2}$ = 3.14 * 100 =314 $cm^{2}$