# Use of Trigonometric functions of angles beyond 90 degrees

I learnt trigonometry recently. we can find the missing lengths or angles of a right angle triangle using the constant ratios.

But what is the utility of trigonometry ratios for angles beyond 90deg??

When do we come across the need of considering such functions with angles more 90deg ?

• The amount of rotation can be any real number, certainly not limited to between $0$ and $90$ degrees. – Robert Israel Jan 14 '14 at 2:56
obtuse angles come up all the time. Perhaps the best example is the longitude that has to go between $-180$ and $180$.