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Question

(add the periods)

For the vectors in the figure, with a = 6.4, b = 2.5 and c = 6.87. Calculate a(dot)b
calculate a(dot)c
calculate b(dot)c

I got 0 for a(dot)b but the same method (ac*cos(theta)) does not work for the other two, please help.

Answer 1

If it does not work, you are not using a common angle reference. Set a line from which you measure all the angles from CLOCKWISE.

I cannot see your picture.

Answer 2

Thank you for responding. You have to replace the spaces with periods (.)