
Brandon R. answered 06/16/20
Experienced Algebra and Geometry Tutor
For right triangles, we use the pythagorean theorem: a2 + b2 = c2 . a and b are the legs of the triangle, and c is the hypotenuse. This question asks about an isosceles right triangles, meaning that the legs are the same length. That length is 8.
82 + 82 = c2
64 + 64 = c2
128 = c2
√128 = c2 <--- Remember from above, we basically had 64 x 2. Square root of 64 is 8.
8√2 = c
You may also remember that right triangles with equal legs are 45-45-90 triangles, and the hypotenuse is equal to x√2 , which is exactly what we got above.