document.write( "Question 253208: how do you find the coordinates of a triangle's vertices by just having the coordinates of its midpoints? \n" ); document.write( "
Algebra.Com's Answer #185440 by drk(1908)![]() ![]() ![]() You can put this solution on YOUR website! Let A, B, and C be the verticies of the triangle. \n" ); document.write( "By definition of midpoint, let \n" ); document.write( "(A+B)/2 = m1 \n" ); document.write( "(A+C)/2 = m2 \n" ); document.write( "(B+C)/2 = m3, \n" ); document.write( "where m1, m1, m3 are midpoints that I assume are given. \n" ); document.write( "Solving using a process called Gauss-Jordan Elimination, we get \n" ); document.write( "Coordinate A = m1 + m2 - m3 \n" ); document.write( "Coordinate B = m1 - m2 + m3 \n" ); document.write( "Coordinate C = -m1 + m2 + m3. \n" ); document.write( "--- \n" ); document.write( "EX: m1 = (0,2), m2 = (3,0), m3 = (3,2) \n" ); document.write( "A = (0,2) + (3,0) - (3,2) = (0,0) \n" ); document.write( "B = (0,2) - (3,0) + (3,2) = (0,4) \n" ); document.write( "C = -(0,2) + (3,0) + (3,2) = (6,0) \n" ); document.write( "--- \n" ); document.write( "The three verticies are: (0,0) (6,0) (0,4). \n" ); document.write( " |