Answer:
a = 7.9 or a = √63
Explanation:
a² + b² = c²
(The two shorter sides of a triangle are always a and b while the longer side will always be c)
So, here the longer side of this triangle is 12 and the shorter sides are 9 and a (unknown).
The equation is: a² + 9² = 12²
But to find the value of a, the formula will be 12² - 9² = a²
12² - 9² = a²
144 - 81 = a²
63 = a²
the square root of 63 = 7.9 so that means a = 7.9