document.write( "Question 195700: There are two similar right triangles.
\n" ); document.write( "The larger triangles hypotenuse is 15 and a leg is 3x, and the other is 3x+3. The smaller triangle has a hypotenuse of 5 one leg is x and the other is x+1.\r
\n" ); document.write( "\n" ); document.write( "How would you write an equation expressing the relationship among the length of the sides of the triangles for the smaller and the larger triangle?\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #146813 by J2R2R(94)\"\" \"About 
You can put this solution on YOUR website!
There are two similar right angled triangles.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The larger triangles hypotenuse is 15 and a leg is 3x, and the other is 3x+3. The smaller triangle has a hypotenuse of 5 one leg is x and the other is x+1.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "How would you write an equation expressing the relationship among the length of the sides of the triangles for the smaller and the larger triangle?\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Going by Pythagoras’ Theorem, the square on the hypotenuse is equal to the sum of the squares of the other two sides, which means:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "For the larger triangle, 15^2 = (3x)^2 + (3x+3)^2\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "225 = 9x^2 + 9x^2 + 18x + 9 = 18x^2 + 18x + 9 = 9 (2x^2 + 2x + 1)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "25 = 2x^2 + 2x + 1 (cancelling by 9)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "giving 0 = 2x^2 + 2x – 24\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "and then 0 = x^2 + x – 12 (cancelling by 2)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We are left with x^2 + x – 12 = 0 = (x + 4)(x – 3) giving x = 3 or -4 but we cannot have a negative length, so the solution is x = 3 units whatever the units are.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "This is the same solution for the smaller triangle since they are similar triangles and every factor has been scaled down by a factor of 3 squared (9) as 3 is the ratio of the larger triangle to the smaller triangle. We would have arrived at 25 = 2x^2 + 2x + 1 without cancelling by 9 if we did to the small triangle what we did to the large triangle.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the sides of the triangles are:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Large: 15, 3x and 3x + 3 giving 15, 9 and 12\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Small: 5, x and x + 1 giving 5, 3 and 4.
\n" ); document.write( "
\n" );