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## Homework Statement

Determine resultanat force of vectors P (40N) and Q (60N). P is 20 degrees from reference plane and Q is 45 degrees from reference plane.

## Homework Equations

When using the parallelogram rule, should you always start with the lowest angle vector? (like in the bottom diagram of the attached image)

## The Attempt at a Solution

I solved the question using the parallelogram in two different ways and ended up with different answers. Is there a right way to do this?

Solution 1:

P vector, then Q vector with resultant vector starting at tail of P to tip of Q.

Law of Cosines yields,

R = 97.726N

Law of Sines yields,

Angle A = ∠15.039

alpha = ∠20 + ∠15.039 = ∠35.04

Solution 2:

Q vector, then P vector with resultant vector starting at tail of Q to tip of P.

Law of Cosines yields,

R = 98.542N

Law of Sines yields,

A = ∠7.9803

alpha = ∠45 - ∠7.9803 = ∠37

Diagram attached.