Many people use “compose” and “comprise” interchangeably.

The pizza comprises 8 slices – CORRECT
The pizza is composed of 8 slices – CORRECT
The pizza is comprised of 8 slices – INCORRECT

“Make up” is an acceptable alternative and can be used in the active or passive voice. The pizza is made up of 8 slices. Eight slices make up the pizza.

We are not making up this rule.