Why does sin54°≈0.809≈cos36° in a right triangle?

A
54° and 36° are complementary angles in the same right triangle. sin54° is the ratio of the opposite leg and the hypotenuse and cos36° is the ratio of the adjacent leg and the hypotenuse. In this triangle, the opposite leg of 54° and the adjacent leg of 36° are the same leg in the triangle.

B
54° and 36° are complementary angles in the same right triangle. sin54° is the ratio of the adjacent leg and the hypotenuse and cos36° is the ratio of the opposite leg and the hypotenuse. In this triangle, the adjacent leg of 54° and the opposite leg of 36° are the same leg in the triangle.

C
54° and 36° are supplementary in the same right triangle. sin54° is the ratio of the opposite leg and the hypotenuse and cos36° is the ratio of the adjacent leg and the hypotenuse. In this triangle, the opposite leg of 54° and adjacent leg of 36° are the same leg in the triangle.

D
54° and 36° are supplementary in the same right triangle. sin54° is the ratio of the adjacent leg and the hypotenuse and cos36° is the ratio of the opposite leg and the hypotenuse. In this triangle, the adjacent leg of 54° and opposite leg of 36° are the same leg in the triangle.

54° and 36° are complementary angles in the same right triangle. sin54° is the ratio of the opposite leg and the hypotenuse and cos36° is the ratio of the adjacent leg and the hypotenuse. In this triangle, the opposite leg of 54° and the adjacent leg of 36° are the same leg in the triangle.

Step-by-step explanation:

The answer explains itself.

The sum of angles in a triangle is 180°. When one of the angles is 90°, the sum of the other two angles is also 90°. That means those two acute angles are complementary (not supplementary).

The mnemonic SOH CAH TOA reminds you that ...

Sin = Opposite/Hypotenuse

Cos = Adjacent/Hypotenuse