document.write( "Question 980091: The area of a triangle is 39 square ft. The length of one side is 1 ft more than teice the altitude to that side. Find the length of that side and the altitude to the side. \n" ); document.write( "
Algebra.Com's Answer #601304 by josh_jordan(263)![]() ![]() You can put this solution on YOUR website! To solve this, we first need to know the formula for the area of a triangle:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We are told that the length of one side (base) is 1 ft more than twice the altitude. In other words b = 2h + 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now, let's replace b in our formula for the area of a triangle with 2h + 1, and A with 39, since that's the area of the triangle:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We can now solve for h (altitude). First, multiply both sides of this equation by 2, which will give us\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(2h + 1)(h) = 39 x 2 -----> (2h + 1)(h) = 78\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Next, multiply (2h + 1) by (h), giving us\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Third, subtract 78 from both sides and enter a 0 on the right side of the equal sign:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Fourth, factor this quadratic equation, which will give us:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Fifth, set each set of parentheses equal to zero and solve for both values of h:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since the height of a triangle cannot be a negative number, we can discard -13/2. So, our altitude (height) is 6 feet.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "To find our length (base), replace the h in 2h + 1 with 6 and compute:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Therefore, the length of this triangle is 13 feet and the altitude is 6 feet. \n" ); document.write( " |