Question

what is angle of resultant in trigonometry​

Answer 1

Answer:

Put in labels for the vertices of the parallelogram. Since opposite angles in a parallelogram are congruent, we can find

Answer 2

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If you subtract 180 degrees from your answer of 45 degrees, you get –135 degrees, which is your actual angle measured from the positive x-axis in the clockwise direction. Alternatively, you could reason that since the components of the vector are both negative, you must be between 180 degrees and 270 degrees.