Answer:
Of course, with a triangle with a 90° angle, a right triangle, you can simply use pythagoras theorem (a2+b2=c2) then SOH-CAH-TOA to solve for the angle (θ=Cos−1(adjacenthypotenuse)) .
But what if it isn't a right triangle? The cosine rule works for all triangles, even if they don't have a 90° angle.
a2=b2+c2−2(b)(c)Cos(A)
Where a is the missing side, and A is the angle opposite to side a.
With this rule, we can find a missing angle or a missing side to any type of triangle, assuming you have the needed variables.
Explanation:
