A 45-45 90 triangle has two lengths that are equal, and the hypotenuse is √2 times those lengths.
Therefore: Let x = the length of a leg (doesn't matter which one, they are equal) √2 * x = 24 Divide both sides by √2 x = 24 / √2 To get the radical out of the denominator, multiply the right side by √2/√2 x = 24√2 / 2 x = 12√2 Answer is B