If this side, let's say it's length a, then this side has length a, so you're going to have a squared plus a squared is equal to the hypotenuse squared, or 2a squared is equal to the hypotenuse squared, or that a squared is equal to the hypotenuse squared over 2, or that a is equal to h over the square root of 2, which is the same thing as the square root of 2h over 2. I just rationalized the denominator, multiplied both the numerator and the denominator by square root of 2. So that's where I got this from. And so what is the area going to be? Well, the area is just going to be your base times your height times 1 half. So let me write that down. So the area there, the area is just going to be the base, which is square root of 2 over 2 times our hypotenuse, times the height, which is square root of 2 over 2 times our hypotenuse, times 1 half.