There are 360 degrees in a circle. The circumference of a circle is the distance around it. It is equal to πd, or 2πr. In this example,
Circumference = πd = 6π.The area of a circle equals π times the square of the radius, or πr^2. In this example, AC is the diameter, so and Area =
πr^2 = π(3^2 ) = 9π.Exercise
Radius = 3Diameter =xvi.