Centroid of a triangle is the point where the three medians of the triangle intersect.
The centroid divides each median into two segments whose lengths are in the ratio 2:1, with the longest one nearest the vertex.
[tex] \cfrac{QP}{PT}= \cfrac{2}{1} \ \ \to \ \ PT= \cfrac{QP*1}{2}= \cfrac{14}{2}=7 \ cm \\ \\ \\ QT=QP+PT=14+7=21 \ cm[/tex]
