I will mark you brainliest :) Use Euler's Formula to find the number of vertices in the given polyhedron.

5 faces: 3 rectangles and 2 triangles

There are ? vertices in the polyhedron.

Here's what I've done so far:

There are 3 sides in a trinangle, so 6 sides in total with 12 sides in total for the rectangles, giving me 18... Now what? THANKS!