document.write( "Question 1134195: TriangleABC~DEF\r
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document.write( "If AB=3, DE=5, BC=9 find the length of EF. \n" );
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Algebra.Com's Answer #751486 by Theo(13342)![]() ![]() You can put this solution on YOUR website! if the triangles are similar, then the corresponding sides are proportional.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this means that the corresponding sides from one triangle to the other have the same ratio.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this means that AB / DE = BC / EF = AC / DF\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "AB / DE = 3 / 5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "BC / EF = 9 / x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x is chosen as the value for the length of EF that you want to solve for.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since the ratios have to be the same, you have 3 / 5 = 9 / x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "cross multiply to get 3 * x = 5 * 9\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get 3 * x = 45\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for x to get x = 45 / 3 = 15\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "your solution is that the length of EF is equal to 15.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have AB / DE = BC / EF which results in 3 / 5 = 9 / 15.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "cross multiply to get 3 * 15 = 5 * 9 which results in 45 = 45, confirming the ratios are the same.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "note that the naming conventions for congruent or similar triangle require that the letters designating the triangle are present in the order of the corresponding sides and angle.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this means that, if triangle ABC is similar to triangle DEF, then:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the corresponding sides are AB to DE, BC to EF, AC to DF and the corresponding angles are A to D, B to E, C to F.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |