Question

How do you know which line is the base and which line is the height in a trapezoid?

Answer 1

Look for Parallel lines.

Explanation:

In a trapezoid, there are 2 bases. The bases are the lines parallel to each other. The other 2 lines are called the legs. Height is the distance of a perpendicular line from a base angle to the opposite base.

Here's a diagram I made that might help clarify