document.write( "Question 1185395: 3. The coordinates of vertex A of the triangle ABC are (7, -4). If the coordinates of the centroid of the triangle are (1, 2), find the coordinates of the midpoint of the side BC \n" ); document.write( "

Algebra.Com's Answer #816226 by greenestamps(13200) $\"\"$ $\"About$

You can put this solution on YOUR website!

\n" ); document.write( "A(7,-4)
\n" ); document.write( "B(a,b)
\n" ); document.write( "C(c,d)

\n" ); document.write( "The coordinates of the centroid are the averages of the coordinates of the three vertices:

\n" ); document.write( " $\"%287%2Ba%2Bc%29%2F3=1\"$
\n" ); document.write( " $\"7%2Ba%2Bc=3\"$
\n" ); document.write( " $\"a%2Bc=-4\"$

\n" ); document.write( " $\"%28-4%2Bb%2Bd%29%2F3=2\"$
\n" ); document.write( " $\"-4%2Bb%2Bd=6\"$
\n" ); document.write( " $\"b%2Bd=10\"$

\n" ); document.write( "The coordinates of the midpoint (m,n) of BC are the averages of the coordinates of B and C:

\n" ); document.write( " $\"m=%28a%2Bc%29%2F2+=+-4%2F2+=+-2\"$
\n" ); document.write( " $\"n=%28b%2Bd%29%2F2+=+10%2F2+=+5\"$

\n" ); document.write( "ANSWER: the midpoint of BC is (m,n)=(-2,5)

\n" ); document.write( " \n" ); document.write( "

\n" );