$\"\"$

Observe the figure : \ \

The point $\"\"$ .

Triangle $\"\"$ is a right triangle with $\"\"$ .

The sides $\"\"$ and $\"\"$ .

Apply Pythagorean theorem : $\"\"$ .

$\"\"$

The three trigonometric functions with $\"\"$ :

$\"\"$ ,

$\"\"$ . $\"\"$

The point is $\"\"$ .

The trigonometric functions are $\"\"$ , $\"\"$ , and $\"\"$ .