document.write( "Question 1100224: Acute isosceles triangle ABC has vertices A(-2,-1), B(3,13), with point C on the line x=-7. If AB=BC, then find the coordinates of C. \n" ); document.write( "

Algebra.Com's Answer #714741 by greenestamps(13200) $\"\"$ $\"About$

You can put this solution on YOUR website!

If AB=BC, then (AB)^2 = (AC)^2; so we can solve the equation that says the squares of the distances are equal.

\n" ); document.write( "Using the distance formula on AB, we find $\"%28AB%29%5E2+=+5%5E2%2B14%5E2+=+221\"$
\n" ); document.write( "Using the distance formula on BC, we find $\"%28BC%29%5E2+=+10%5E2+%2B+%2813-y%29%5E2\"$

\n" ); document.write( "Then
\n" ); document.write( " $\"221+=+100+%2B+%2813-y%29%5E2\"$
\n" ); document.write( " $\"121+=+%2813-y%29%5E2\"$
\n" ); document.write( " $\"11+=+13-y\"$
\n" ); document.write( " $\"y+=+2\"$

\n" ); document.write( "Point C is (-7,2) \n" ); document.write( "

\n" );