What is an easier way to solve to find a missiNg angle?

(180 method)

Let's say you are trying to find the angle A.

The only clues: 75 and 70

So you know that a whole shape would add up to 180

So 75+70+A would equal to 180.

So 75+70 = 145

180-145 = 35

So A = 35