A circle has a radius of 6 inches. find the area of the semicircle.
Solution.
Area of a semi-circle =
[tex]\begin{gathered} \frac{1}{2}\text{ }\pi r^2 \\ \text{but r = 6 inches , }\pi\text{ =}\frac{\text{ 22}}{7} \\ \text{Area = 1/2 x 22/7 x 6 x 6} \\ \text{ = 56 4/7 inches}^2 \\ =56.52inches^2 \end{gathered}[/tex]The circumference of a circle is 16 pie. what is the circles area?
Solution:
[tex]\begin{gathered} \text{Circumference = 2 }\pi\text{ r = 16 }\pi \\ \text{ 2 r = 16} \\ \text{ r = 16/2} \\ \text{ r = 8} \\ \text{Area of the circle = }\pi\text{ }\times r^2 \\ \text{ = }\pi\text{ }\times8^2 \\ \text{ = 64 }\pi units^2 \end{gathered}[/tex]