Question

Which of the following explains why cos60 = sin30 using the unit circle?

A.) The side opposite a 30° angle is the same as the side adjacent to a 60° angle in a right triangle. On a unit circle, the y (sin) distance of a 30° angle is the same as the x (cos) distance of a 60° angle.
B.) The side opposite a 30° angle is the same as the side adjacent to a 60° angle in a right triangle. On a unit circle, the x (sin) distance of a 30° angle is the same as the y (cos) distance of a 60° angle.
C.) The ratios describe different sides of the same right triangle. On a unit circle, the y (sin) distance of a 30° angle is the same as the x (cos) distance of a 60° angle.
D.) The ratios describe different sides of the same right triangle. On a unit circle, the x (sin) distance of a 30° angle is the same as the y (cos) distance of a 60° angle.

Answer 1

A is the correct answer. The sine pertains to the opposite side of a right triangle while cosine pertains to the adjacent side. On the unit circle, x represents cosine and y represents sine.

Answer 2

Hey there

Statement (A) tells us why cos60 = sin30 using the unit circle.

(A) = The side opposite a 30° angle is the same as the side adjacent to a 60° angle in a right triangle. On a unit circle, the y (sin) distance of a 30° angle is the same as the x (cos) distance of a 60° angle.