This cylindrical fish tank has a height of 36 inches and a diameter of 30 inches. What is the volume of the fish tank?

The formula for the volume of a cylinder is:
area of cross-section x the height.

First lets work out the area of the cross-section. Since the cross-section is a circle, we use the formula π x r²

Halve the the diameter to get the radius, so we can use the formula:
30 / 2 =15

Area of cross-section
π x 15² = 706.8583471 inches²


Now that we know the area of the cross-section, we multiply this by the height to get the volume.

706.8583471 x 36 = 25446.90049
                                 = 25446.90 (2dp)

So the volume of the cylindrical fish tank is  25446.90