**Two angles are allied if their sum or difference is a multiple of 90 ^{o}**.

If is any angle, then etc are called as **allied angles**.

__General trigonometric ratios and allied terms are listed below__:

__Example:__

The value of trigonometric function is;

We know that, , then;

__Question 1:__

Find the value of trigonometric function

*Solution*

We know that, , then;

__Question 2:__

Find the value of trigonometric function

*Solution*

is written as

Known that, , then;