Geometry: Measurements

Problem : What is the area of a circle with diameter 8?

Problem : If a central angle is 120 degrees, and the radius is 3, what is the area of the sector defined by the intersection of the angle and the circle?

Problem : What is the area of the shaded region below?

Problem : If the radius of circle A is twice that of circle B, how many times greater is the area of circle A than circle B?

Problem : What is the area of the shaded region?