document.write( "Question 726772: Please show me how to solve this word problem:\r
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document.write( "The width of a rectangular parking lot is 53ft less than its length. Determine the dimensions of the parking lot if it measures 220ft diagonally.
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Algebra.Com's Answer #444789 by DrBeeee(684)![]() ![]() ![]() You can put this solution on YOUR website! Let w = the width of the driveway. \n" ); document.write( "Let l = the length of the driveway. \n" ); document.write( "Let d = the diagonal of the driveway. \n" ); document.write( "The diagonal of a rectangle is the hypotenuse of the right triangle with legs equal to length and width. \n" ); document.write( "We are given that \n" ); document.write( "(1) l = w + 53 and \n" ); document.write( "(2) d = 220 \n" ); document.write( "Applying the Pythagorean theorem yields \n" ); document.write( "(3) d^2 = l^2 + w^2 or \n" ); document.write( "(4) 220^2 = (w+53)^2 + w^2 or \n" ); document.write( "(5) w^2 + 106w + 53^2 + w^2 - 220^2 = 0 or \n" ); document.write( "(6) 2w^2 + 106w - 45591 = 0 or \n" ); document.write( "(7) w^2 + 53w - 45591/2 = 0 \n" ); document.write( "Using the positive square root in the quadratic equation gives us \n" ); document.write( "(8) w = (-53 + sqrt(53^2 + 2*45591))/2 or \n" ); document.write( "(9) w = (-53 + sqrt(2809 + 91182)/2 or \n" ); document.write( "(10) w = (-53 + sqrt(93991)/2 or \n" ); document.write( "(11) w = (-53 + 306.579...)/2 or \n" ); document.write( "(12) w = (253.579...)/2 or \n" ); document.write( "(13) w = 126.789... \n" ); document.write( "Then using (1) we get \n" ); document.write( "(14) l = 179.789... \n" ); document.write( "Let's check w and l using (3). \n" ); document.write( "Is (220^2 = (179.789...)^2 + (126.789...)^2)? \n" ); document.write( "Is (220^2 = 32324.357... + 16075.643...)? \n" ); document.write( "Is (48400 = 48400)? Yes \n" ); document.write( "Answer: The parking lot is 179.789... ft by 126.789... ft. \n" ); document.write( " \n" ); document.write( " |