Question

how to find a missing angle in a right triangle with side lengths

Answer 1

the lengths of angles in triangles always add up to 180°

take the 2 sides and add them and subtract from 180

Answer 2

First a triangle is always 180
So the steps are:
1. Add I’ll all the sides
2. Do 180 minus whatever you got when you added all the sides together

That’s what you do I hope this helps!