3) A stationary box is acted upon by 5 forces represented by letters of the alphabet as shown figure 1. Under which of these conditions will the box move in the direction shown in figure 2? Assume a frictionless surface. a) S=P+Q and T P or =P and T >Q+R

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:

probably not if net force is zero