
Lauren D. answered 04/23/21
Fun and Committed K-6 Tutor Specializing in STEM Fields
Hi Alex!
In the image above we can see that there is a 90 degree angle between lines a and b and there is a line pointing towards c. Line C is our hypotenuse because it is the line adjacent to the 90 degree angle. Using the "leg" rule (link below) you can calculate how to find the height of your triangle using the measurements given and your hypotenuse.
https://www.mathematicalway.com/mathematics/geometry/leg-rule/
Or if you just needed to know the line in general, Line C (your hypotenuse line) is going to be the line along with the line directly above or below it (the base) that you'll use for triangle height.