Question

Calculate the length of a triangle if another length is 15 feet and the hypotenuse is 39 feet.

Answer 1

We have to use Pythagorean theorem that says : 

$a^2+b^2=c^2\\\Rightarrow a^2+15^2=39^2\\a^2=39^2-15^2\\a=\sqrt{1296}\\a=36$

The missing length of the triangle is : 36 feet