document.write( "Question 1203428: biologist wants to know the width w of a river so that instruments for studying the pollutants in the water can be set properly. From point A, the biologist walks downstream 100 feet and sights to point C (see figure). From this sighting, it is determined that θ = 58�. How wide is the river?
\n" ); document.write( "Please explain each step.
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Algebra.Com's Answer #838987 by Theo(13342)\"\" \"About 
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B is 100 feet from point A.
\n" ); document.write( "C is assumed to be directly across the river.
\n" ); document.write( "ABC right triangle is assumed.
\n" ); document.write( "AB is 100 feet long on one side of the river.
\n" ); document.write( "BC is perpendicular to AB with point C on the other side of the right.\
\n" ); document.write( "angle CAB is 58 degrees.
\n" ); document.write( "tan(CAB) = opposite / adjacent = BC / AB = BC / 100
\n" ); document.write( "since CAB is 58 degrees, you get tan(58) = BC / 100
\n" ); document.write( "solve for BC to get BC = 100 * tan(58) = 62.48693519 feet.
\n" ); document.write( "that's the width of the river.
\n" ); document.write( "here's my diagram.
\n" ); document.write( "if it's not accurate, please send an accurate picture.
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