The hypotenuse of a right triangle is equal to the square root of the two sides raised to the second power added together.
This is known as the Pythagorean theorem.
a^2 + b^2 = c^2
27 well if you're asking that then
Some number y has 7 subtracted off to get 15. We have y-7 = 15. To isolate y, we have to undo the "subtract 7" operation that happens to y. We have to add 7 to both sides.
y-7 = 15
y-7+7 = 15+7
y = 22 is the answer
