Question 1172079: A line AB, 125 feet long, is measured along the straight bank of a river. A point C is on the opposite bank. Angles ABC and BAC are found to be 65 degrees 40' and 54 degrees 30' respectively. How wide is the river?
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! Draw this with
=====C====
B-------------A
sin B=0.9111
sin A=0.8141
From these side b (AC) is by the Law of Sines 132.18 ft
side a (BC) is 118.11 ft.
Now draw a perpendicular from C to AB, reaching at point D.
This creates two right triangles, ADC and BDC.
Again by the Law of Sines (easier with a 90 degree angle as one of them and using the original angles again), CD, the distance across the river, is 107.61 feet.
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