Question

Find the sin and cos of theta.

(diagram)

Answer 1

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

Answer 2

\[\cos \theta=\frac{-5}{13}\]

Answer 3

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

Answer 4

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

Answer 5

how do you find the reference angle?

Answer 6

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