Consider objects in the shape of a right polyhedron and a straight circular cylinder. The volume of the object can be thought of as being formed by two-dimensional pieces that coincide with the base.

The measurement accuracy at which the heights of the figures (here [[$ c $]] and [[$ h $]]) are given can be thought of as the thickness of the objects. If the height is given to the nearest centimeter, the objects are one centimeter thick.

The volumes of a cylinder is always calculated in the same way, irrespective of its base shape or whether it is straight or oblique.

Note! If the cylinder is oblique, the height is the distance from the bottom measured perpendicular to the cylinder head.

Example 1

Calculate the volume of the Leaning Tower of Pisa in Italy. Assume that the tower is the same width throughout. The diameter of the tower's base is [[$ 15.5 $]] m, and its height is [[$ 55.9 $]] m.

The tower is in the shape of a circular cylinder with a base area of [[$ A_p = \pi r^2 $]]​ and the height [[$ h $]]​, so the volume can be calculated with the formula [[$ V = \pi r^2h $]]​.

​[[$ \begin{align*} V &= \pi r^2h \\ &= \pi \cdot 7,75 \;\text{m}^2 \cdot 55,9 \;\text {m} \\ &= 10\;547,87... \;\text {m}^3 \\ &≈ 10\;500 \;\text {m}^3 \\ \end{align*} $]]​

Answer: The volume of the Leaning Tower of Pisa is [[$ 10\;500 \;\text m^3 $]]​.

If the calculation had been more accurate, what should have been taken into account?