Step-by-step explanation:
Step 1: find the names of the two sides we know
triangle showing Opposite, Adjacent and Hypotenuse
Adjacent is adjacent to the angle,
Opposite is opposite the angle,
and the longest side is the Hypotenuse.
Example: in our ladder example we know the length of:
the side Opposite the angle "x", which is 2.5
the longest side, called the Hypotenuse, which is 5
Step 2: now use the first letters of those two sides (Opposite and Hypotenuse) and the phrase "SOHCAHTOA" to find which one of Sine, Cosine or Tangent to use:
SOH...
Sine: sin(θ) = Opposite / Hypotenuse
...CAH...
Cosine: cos(θ) = Adjacent / Hypotenuse
...TOA
Tangent: tan(θ) = Opposite / Adjacent
In our example that is Opposite and Hypotenuse, and that gives us “SOHcahtoa”, which tells us we need to use Sine.
Step 3: Put our values into the Sine equation:
Sin (x) = Opposite / Hypotenuse = 2.5 / 5 = 0.5
Step 4: Now solve that equation!
sin(x) = 0.5
Next (trust me for the moment) we can re-arrange that into this:
x = sin-1(0.5)
And then get our calculator, key in 0.5 and use the sin-1 button to get the answer:
x = 30°
JUST EXAMPLE
