To find the circumference of a circle, you multiply the diameter(15) to pi (3.14).
To find the area of a circle, you find the radius of the circle, which is half of the diameter (7.5), square it, which equals 56.25, multiply that by pi (3.14) and there is your area. Make sure to write your answer to area in square inches.
We know that The sum of exterior angles of any polygon is 360 degrees. Each exterior angle of a regular polygon = 360/n where n is the number of sides. <span>So n = 360/20 = 18 </span> the answer is the option <span>b.18 </span>
