2

Set 3: Trigonometry (Intermediate)

Explanation

Answer: A

PROBLEM

Intriguingly, in a right triangle, the opposite side is 5, adjacent side is 12, and hypotenuse is 13. Find cos(angle).

In a right triangle, the opposite side is 5, adjacent side is 12, and hypotenuse is 13. Find cos(angle).

A.

12/13

✓ Correct
B.

5/12

C.

13/5

D.

12/13

Detailed Explanation

[Variation 2] Choice A is the best answer. cos = adjacent/hypotenuse = 12/13

Why others are wrong:
B: 5/12 is incorrect because it does not satisfy the equation.
C: 13/5 is incorrect because it does not satisfy the equation.
D: 12/13 is incorrect because it does not satisfy the equation.