Answer:
12 in
Explanation:
Pythagoras' Theorem: a² + b² = c²
(where a and b are the legs, and c is the hypotenuse, of a right triangle)
let x = unknown side
Given:
Substituting the given values into the equation:
⇒ x² + 9² = 15²
⇒ x² + 81 = 225
⇒ x² + 81 - 81 = 225 - 81
⇒ x² = 144
⇒ x = √(144)
⇒ x = ±12
As the length is positive, x = 12 only.
Therefore, the length of the unknown side is 12 in.