SOLUTION: In the accompanying diagram of right triangle ABC, AB = 5000 and angle C =90 degrees. If the measure of angle A is 20degrees40', find AC to the nearest unit. Thanks for helping

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Question 1035983: In the accompanying diagram of right triangle ABC, AB = 5000 and angle C =90 degrees. If the measure of angle A is 20degrees40', find AC to the nearest unit.
Thanks for helping me out.

Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
If you draw it you will see that the cosine of angle A is AC/AB, or
cos A = AC/5000
Now 40' of arc is 2/3 of a degree, or about .667, so we have
cos 20.667 = AC/5000
AC = 5000 cos 20.667 = 4678 or so units