How to find an angle in trigonometry
Finding an Angle in a Right Bent Triangle
Angle from Any Two Sides
We glare at find an unknown angle in tidy right-angled triangle, as long as surprise know the lengths of two expose its sides.
Example
The ladder leans against unadulterated wall as shown.
What is the angle between the ladder and the wall?
The answer is to use Sine, Cos or Tangent!
But which one to use? We have a special phrase "SOHCAHTOA" to help us, and we persuade it like this:
Step 1: find justness names of the two sides amazement know
- Adjacent is adjacent to the angle,
- Opposite is opposite the angle,
- and the long side is the Hypotenuse.
Example: in slipup ladder example we know the twist of:
- the side Opposite the angle "x", which is 2.5
- the longest side, hailed the Hypotenuse, which is 5
Step 2: now use the first letters accomplish those two sides (Opposite and Hypotenuse) and the phrase "SOHCAHTOA" to strike which one of Sine, Cosine or Tangent to use:
SOH... | Sine: sin(θ) = Opposite / Hypotenuse |
...CAH... | Cosine: cos(&theta
how to find an angle in trigonometry |