For the right triangle shown, which equation is correct?

 A) sin 59° = cos 31°

Step-by-step explanation:

Based on the angle and the sides provided, we can establish that

tan 31° = 17/x

Since no hypotenuse is provided and we cannot solve for it, we can rule out options B, C, and D.

We know that the sum of the angles of a triangle is 180°. In a right triangle, we know that one of the angles is 90°, so the other two angles are complimentary  -->   sin Ф = cos (90 - Ф).

Therefore, option A is true.