Simple trigonometry can be used with right angled triangles to find an angle given two sides, or a side given a side and one of the interior angles other than the right angle,
With the sides of the triangle as labelled above, we can use one of the formulae:
Example: Finding an angle using cos
For the triangle above, we have
and
and want to find
This means we use
Example: Finding an angle using tan
For the triangle above, we have
andand want to findThis means we use
Example: Finding an angle using sin
For the triangle above, we haveandand want to findThis means we use