Question

The below is from an Ontario Calculus course (Pre Uni). I’m not sure how, in part two, theta of 69.6 degrees was

found — did the course use the sine law correctly? By my calculations, the angle that the resultant makes with V is 38.68 degrees (if we use u = 2).

Please don’t explain the step using cosine law, just focus on the sine law part.

Thanks.

Trigonometry