Question 856787
(leg)^2 + (leg)^2 = (hypotenuse)^2

Let h = hypotenuse for short writing

(12)^2 + (16)^2 = h^2

144 + 256 = h^2

400 = h^2

sqrt(400) = sqrt(h^2)

20 = h

The hypotenuse is 20.