Question

[GEOMETRY] I now know that x=96 and y=42. But why is this? Is there an easier a to think about questions like this?

Please refer to the photo.

Answer 1

Triangle is isosceles, so the angles opposed to equal sides are equal, so you can write down a condition, in this case y=42 (the two equal angles are marked with the line). x is found by difference, since the internal angles sum to 180, and it's the solution to x + 42 + 42 = 180, so 96.

Most of these kind of problems are solved with this system: identify if there are equal angles (ie, they're part of an isosceles triangle, or if they are opposite by a vertex) and write equations based on them