Answer:
A
Step-by-step explanation:
Tangent if Opposite over Adjacent.
The Opposite side from angle A is 12 in.
We need to find the adjacent side using pythagorean theorem.
a² + b² = c²
12² + b² = 40²
144 + b² = 1600
b² = 1456
b = 4√91
So Tan A = 12/4√91
Simplify to get the radical out of the denominator
12√91/4·91 = 3√91/91 A.
