In this challenge, we’re trying to find the area of this triangle, with perimeter 20. Now, it is important to recognize that this is an isosceles triangle. That means that 2 sides are equal, and the third side is bisected. That means that if we let x and y be the side lengths, x+2y=20. Also, using the pythagorean theorem, x2 /2+25 = y2. The only solution to this is x=7.5, and y=6.25. That makes the area 5x/2, or 18.75 u2