How do you calculate the circumference of a circle when you know the diameter?

Adecorative window is made up of a rectangle with semicircles at either end. the ratio of ad to ab is 3: 2 and ab is 30 inches. what is the ratio of the area of the rectangle to the combined area of the semicircles? possible answers: a. 2: 3 b. 3: 2 c. 6: π d. 9: π e. 30: π

18 16 11 45 33 11 33 14 18 11 what is the mode for this data set

The base of the rectangle pyramid is 13 inches long and 12 inches wide the height of the pyramid is 18 inches . what is the volume of the pyramid ?