Unit Circle: Complementary Angles

This sketch shows the relationship between an angle

and its complement,

. Drag

around the circle and notice what happens to

. How are the trigonometric ratios of the angles related?

What is the geometric relationship between

and

The coordinates of

are

. From the relationship described in question 1, what are the coordinates of

Since

is a point on the unit circle corresponding to the angle

in standard position, it has coordinates:

Therefore, for any angle

, we have:

Information: Unit Circle: Complementary Angles