this would apply with the rule of 45, 45, 90 (degrees) the 2 legs would equal 3, as shown on the paper making the hypotenuse (the longer side) 3 to the square root of 2. the hypotenuse will always be the number on the leg to the square root of 2, and vise versa.
for example if there is a problem that only gives you the hypotenuse (let’s say 6 to the square root of 2) then the two legs would be 6