Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 3 - No. 17)

What is the relationship between sine and cosine in the context of a right-angled triangle?

Sine and cosine are equal

Sine and cosine are inverses of each other.

Sine of an angle equals cosine of its complement.

Sine and cosine are unrelated.

The sine of an angle is equal to the cosine of its complement.