With a triangle that you already know two angles, you can find the third one fairly easily by adding the two you already have, and then subtracting that sum from 180. Now that you have the third angle measure, you know that you have an isosceles triangle, because two of the angle measures are 45. Then, you know that two sides of the triangle are equal (both legs). Since they are equal, you know that those two legs squared added up equal 3 sqrt2 squared, or 18. Now you have to solve this equation, x squared + x squared = 18, or when you simplify, x = 3. That's the answer!
