The trigonometric equation is
.
Rewrite the trigonometric equation as
.
The trigonometric function :
.
The length of hypotenuse is
.
The length of adjacent side is
.
Find the length of opposite side.
\Pythagorean Theorm :
.

The length of opposite 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
.