The trigonometric equation is .
Rewrite the above trigonometric equation as .
Trigonometric function : .
The length of opposite side is .
The length of hypotenuse is .
Find the length of adjacent side.
\Pythagorean Theorem : .
The length of adjacent side is .
\
If the ratio of the sides are then the ratio of angles are
.
Observe the diagram.
\The acute angle is
.
The acute angle is
.