9514 1404 393
Answer:
2√71
Explanation:
The Pythagorean theorem tells you the square of the hypotenuse is the sum of the squares of the other two sides. Let x represent the length of the hypotenuse.
x^2 = 15^2 +(√59)^2
x^2 = 225 +59 = 284
x = √284 = 2√71
In simplest form, the third side is 2√71.