To find the missing length of a triangle we will use the Pythagorean Theorem.
Pythagoream Theorem = a^2 + b^2 = c^2
With this formula, we can find the missing side as follows:
27^2 + 36^2 = c^2
729 + 1,296 = C
2,025 = C
45 = C^2
There for we can conclude that the answer for the missing side is: 45 inches.