The perimeter would be about 34.4 because if you choose the bottom side to be ten, by multiplying 35 by 2 to get 70 you can divide by 10 to get 7. Since you know the height and width, you can use pythagorean theorem, a^2 + b^2 = c^2. Plug in the numbers you have 10^2+7^2=c^2. c^2=149, so if you square root 149 you will get a irrational number but when rounded you get 12.2- so that is one side multiply by 2 and get 24.4- and add 10 to get 34.4