\begin{definition}[Definition:Cylinder/Similar Cylinders]
Let $h_1$ and $h_2$ be the heights of two cylinders.
Let $d_1$ and $d_2$ be the diameters of the bases of the two cylinders.
Then the two cylinders are '''similar''' {{iff}}:
:$\dfrac {h_1} {h_2} = \dfrac {d_1} {d_2}$
{{EuclidSaid}}
:''{{Definition:Euclid's Definitions - Book XI/24 - Similar Cones and Cylinders}}''
{{EuclidDefRefNocat|XI|24|Similar Cones and Cylinders}}
Category:Definitions/Cylinders
\end{definition}