Use the sine, cosine, or tangent ratio to write equations involving ∠A.
In both cases we got m∠A=67.38^(∘).
Practice makes perfect
Since we have all three sides of the right triangle, we can use the sine, cosine, or tangent ratio to write an equation involving ∠A.
&sin θ=Opposite/Hypotenuse [0.8em]
&cos θ=Adjacent/Hypotenuse [0.8em]
&tan θ=Opposite/Adjacent
Let's write all of these equations for the given triangle, and then we will choose which ones we want to use to calculate the desired angle.
To solve these equations we have to perform the inverse operation to the trigonometric function that was used. Let's solve the equations with the sine and cosine ratio.
