document.write( "Question 233387: Points A and B are separated by a lake. To find the distance between them, a surveyor locates a point C on land such that angleCAB = 48.6°. He also measures CA as 316 ft and CB as 527 ft. Find the distance between A and B. Round your answer to the nearest foot. (Note: angleABC is an acute angle.) \n" ); document.write( "
Algebra.Com's Answer #172300 by Theo(13342)![]() ![]() You can put this solution on YOUR website! Drop a line perpendicular to line AC and intersecting line AC at point D.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "That forms 2 right triangles.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "First is triangle ACD and second is triangle BCD.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "You have:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "AC = 316 feet (given) \n" ); document.write( "BC = 527 feet (given) \n" ); document.write( "angle CAB = 48.6 degrees (given) \n" ); document.write( "angle CAD = 58.6 degrees also because it's the same angle.\r \n" ); document.write( "\n" ); document.write( "sin(CAD) = CD / AC \n" ); document.write( "This becomes: \n" ); document.write( "sin(48.6) = CD / 316 \n" ); document.write( "multiply both sides of this equation to get: \n" ); document.write( "316 * sin(48.6) = CD \n" ); document.write( "This makes CD = 237.035098\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We use the value of CD to get angle CBD\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sin(CBD) = CD / 527 \n" ); document.write( "This becomes: \n" ); document.write( "sin(CBD) = 237.035098/527 = .44978197 \n" ); document.write( "This makes angle CBD = 26.72969621 degrees.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We can now find AD and BD.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "cos(CAD) = AD / AC \n" ); document.write( "This becomes: \n" ); document.write( "cos(48.6) = AD / 316 \n" ); document.write( "multiply both sides of this equation by 316 to get: \n" ); document.write( "316 * cos(48.6) = AD \n" ); document.write( "This makes AD = 208.9745494 feet.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "cos(CBD) = BD / BC \n" ); document.write( "multiply both sides of this equation by BC to get: \n" ); document.write( "BC * cos(CBD) = BD \n" ); document.write( "This becomes: \n" ); document.write( "527 * cos(26.72969621) = BD \n" ); document.write( "This makes BD = 470.6859304 feet\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Total length of AB = AD + BD = 208.9745494 + 470.6859304 = 679.6584798 feet.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |