Question

What is the hypotenuse of a right triangle whose catheters are 3 and 4? Imercian reader

Answer 1

By the Pythagorean theorem we have

$a^2+b^2=c^2$ (1)

in the right triangle $ABC$ (see the picture below). Here is $a$ and $b$ are legs and $c$ is the hypotenuse. From (1) it follows that

$c^2=3^2+4^2=25,$

$c=5.$