Set 4: Trigonometry (Intermediate)

[Variation 3] **Choice A is the best answer.** cos = adjacent/hypotenuse = 12/13

Explanation

Answer: A

PROBLEM

Researchers have observed that 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).

12/13

✓ Correct

13/5

5/12

12/13

Detailed Explanation

[Variation 3] Choice A is the best answer. cos = adjacent/hypotenuse = 12/13

Why others are wrong:

B: 13/5 is incorrect because it does not satisfy the equation.

C: 5/12 is incorrect because it does not satisfy the equation.

D: 12/13 is incorrect because it does not satisfy the equation.