document.write( "Question 107935: The diagonal of a rectangle is 2 ft longer than its length and 5 feet longer than its width. What are the dimensions of the rectangle? \n" ); document.write( "
Algebra.Com's Answer #78686 by edjones(8007)![]() ![]() You can put this solution on YOUR website! The diagonal divides the rectangle into 2 equal right triangles. \n" ); document.write( "Let the diagonal=c and the 2 sides be a and b. \n" ); document.write( "a=c-2, b=c-5 \n" ); document.write( "a^2+b^2=c^2 \n" ); document.write( "(c-2)^2+(c-5)^2=c^2 \n" ); document.write( "c^2-4c+4+c^2-10c+25=c^2 \n" ); document.write( "c^2-14c+29=0 \n" ); document.write( "c^2-14c =-29 \n" ); document.write( "c^2-14c+49=49-29 complete the square \n" ); document.write( "(c-7)^2=20 \n" ); document.write( "c-7=+-sqrt(20) \n" ); document.write( "c=7+-sqrt(5*4) \n" ); document.write( "=7+-2sqrt(5) \n" ); document.write( "Only 7+2sqrt(5) is the only correct answer for the diagonal. the other would lead to negative numbers for the sides of the rectangle. \n" ); document.write( "The sides of the rectangle are: \n" ); document.write( "5+2sqrt(5) and 2+2sqrt(5) \n" ); document.write( "Ed \n" ); document.write( " |