Volume of a cylinder = pi * r^2 * h
325 pi = pi * 5^2 * h divide out pi
325 = 25 * h divide both sides by 25
13 cm = h
For the second one...let's let the original dimensions = 1 x 7
If the scale factor is 16:1 .....each dimension in the actual house is 16 times as much...so the area is
7* 16 * 1 * 16 =
7 * 16^2 = 1792 ft^2
Last one
The diagonal is the hypotenuse of a right triangle and "12" is the length of one of the legs......the other leg will represent the other dimension of the rectangle
So its length is
sqrt ( 18^2 - 12^2) = sqrt (180)
So the perimeter is 2 (12 + sqrt (180) ) = 50.83 in