I took a practice SAT test, and I didn't do as well on the math portion as I was hoping to. I ran into a problem like this (not geometry, but one that took me too much time) in each section and didn't have time to check my work..
Anyway, the problem shows a flag like this (not drawn to proportion) and gives the following information: the flag is made of two identical, intersecting equilateral triangles. All three line segments on the right hand side are 10 inches long.
It asks for the perimeter of the flag...
I didn't figure out how to solve the problem until after I had taken the test and thought about it. It took me too long to realize that the length of the sides of the larger triangles was 20 inches. I still don't have a mathematical basis for knowing that, it just logically made sense.
What conclusions should I have made upon seeing the flag and reading the information? What would have been the best way to solve this?