Notice that △ GHK is a right triangle. To find GH we will use the Pythagorean Theorem.
GK^2 + KH^2 = GH^2
We already know that GK = 12 and KH = 15. Let's substitute these values into the above equation and solve for GH.
Wehn solving the equation, we only considered the principal root. The reason for this is that GH is the length of a segment and therefore cannot be negative.
