Find the length of segment BC if segment BC is parallel to segment DE and segment DC is a medsegment of triangle ABC.

A(-3,4) E(4,3) D(1,1)
B and C do not have coordinates

2 answers

A diagram will help solve these geometry problems.

If DC is a mid-segment, i.e. D is at the mid point of AB of triangle ABC, then mAD=mDB and since DE is parallel to BC, mAE=mEC.

By similar triangles, mBC = 2* mDE
The length of
mBC=2*sqrt((Ex-Dx)²+(Ey-Dy)²)
=2*sqrt((4-1)²+(3-1)²)
=2*sqrt(13)