document.write( "Question 473138: A garden shaped like a right trianglr has one leg 6 meters less that the length of the other. The hypotenuse is 6 meters less than 2 times the length of the shorter leg. What are the lengths of the sides? \n" ); document.write( "
Algebra.Com's Answer #324428 by karaoz(32)![]() ![]() You can put this solution on YOUR website! There are three unknown values: \n" ); document.write( "a = shorter leg \n" ); document.write( "b = longer leg \n" ); document.write( "c = hypotenuse \n" ); document.write( " Translation of the relevant information into algebraic statements: \n" ); document.write( "b = a + 6 \n" ); document.write( "c = 2a - 6 \n" ); document.write( "a = ? \n" ); document.write( "b = ? \n" ); document.write( " So, there are three variables and only two equations. \n" ); document.write( "To be able to solve the system we need one more equation. \n" ); document.write( "This equation will come from the fact that the triangle is a right triangle. \n" ); document.write( "For any right triangle, it is true that a2 + b2 = c2 and this will be our third equation. \n" ); document.write( "Hence the system to solve is: \n" ); document.write( "b = a + 6 \n" ); document.write( "c = 2a - 6 \n" ); document.write( "a2 + b2 = c2 \n" ); document.write( " We can quickly reduce the system by substituting b and c in the third equation by the expressions on the right hand sides of the first two equations. \n" ); document.write( "This will give us: \n" ); document.write( "a2 + (a + 6)2 = (2a - 6)2, \n" ); document.write( "which is one equation with one unknown. \n" ); document.write( " After squaring the expressions in brackets, we have \n" ); document.write( "a2 + a2 + 12a + 36 = 4a2 -24a + 36 \n" ); document.write( " After simplifying, the equation becomes: \n" ); document.write( "2a2 - 36a = 0, which is equivalent to: \n" ); document.write( "2a(a - 18) = 0 \n" ); document.write( " There are two solutions to this equation: a = 0 and a = 18. \n" ); document.write( "If a = 0 then b = 6 and c = -6, which is clearly not a real triangle even though the values satisfy all the three equations. \n" ); document.write( "So, we will disregard this solution and keep only a = 18. \n" ); document.write( " When a = 18 then b = 24 and c = 30. \n" ); document.write( "So the answer to the question is: \n" ); document.write( "The lengths of the sides are 18 meters and 24 meters.\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |