document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1203428>Question 1203428</A>: <I><SPAN STYLE=\"word-break: break-all;\">  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? <BR>\n" );
document.write( "Please explain each step. <BR>\n" );
document.write( "Thank you  </SPAN>\n" );
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document.write( "Assuming that the tutor @MathLover1 has the correct diagram, then,\r<BR>\n" );
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document.write( "tan(angle) = opposite/adjacent<BR>\n" );
document.write( "tan(58) = w/100<BR>\n" );
document.write( "w = 100*tan(58)<BR>\n" );
document.write( "w = 160.033452904106<BR>\n" );
document.write( "w = 160.03\r<BR>\n" );
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document.write( "The width of the river is roughly 160.03 feet.\r<BR>\n" );
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document.write( "As a side note, tan(45) = 1.<BR>\n" );
document.write( "Because tangent is an increasing function, this must mean tan(58) > 1 and 100*tan(58) > 100 without needing a calculator.<BR>\n" );
document.write( "It's not entirely clear how the tutor @Theo got 100 * tan(58) = 62.48693519 which is not correct.\r<BR>\n" );
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document.write( "If I had to guess, Theo made this calculation<BR>\n" );
document.write( "100 / tan(58) = 62.48693519<BR>\n" );
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