Consider the given figure in which PQ is a line segment drawn through the mid-point P of line AB, such that PQ || BC
By using the proportionality theorem, we obtain
\(\frac{AQ}{QC}=\frac{AP}{PB}\)
\(\frac{AQ}{QC}=\frac{1}{1}\)
\(\Rightarrow\)AQ = QC
Or, Q is the midpoint of AC