## anonymous 4 years ago Find the sin and cos of theta. (diagram)

1. anonymous

|dw:1328328468937:dw|

2. Mertsj

Remember that sin is side opposite/hypotenuse and cos = side adjacent/hypotenuse. $\sin \theta = \frac{12}{13}$

3. Mertsj

$\cos \theta=\frac{-5}{13}$

4. anonymous

theta doesn't equal 360 minus the angle between 5 and 13, just 180 minus that angle... is it still that simple?

5. Mertsj

So yes. After you find your reference angle, subtract it from 180 to get the angle measured counterclockwise from the positive x axis.

6. anonymous

how do you find the reference angle?

7. anonymous

depends on which quadrant you are in: Let A be the angle, R be reference angle Quad 1: R =A Quad 2: R = 180-A Quad 3: R = A-180 Quad 4: R = 360 -A