If two sides AB and BC, and the median AD of △ABC are correspondingly equal to the two sides PQ and QR, and the median PM of △PQR. Prove that △ABC≅△PQR.
Answer:
- We are given that AB=PQ, BC=QR, and AD=PM.
Let us now draw the triangles and mark the equal sides and medians. - We need to prove that △ABC≅△PQR.
- It is given that BC=QR⟹12BC=12QR⟹BD=QM…(1) [As the median from a vertex of a triangle bisects the opposite side.] Now, in △ABD and △PQM, we have AD=PM[Given]AB=PQ[Given]BD=QM[From (1)]∴
- As corresponding parts of congruent triangles are equal, we have \angle B = \angle Q \space \space \space \ldots (2)
- In \triangle ABC and \triangle PQR, we have \begin{aligned}
& BC = QR && [\text{Given}] \\
& AB = PQ && [\text{Given}] \\
& \angle B = \angle Q && [\text{From (2)}] \\
\therefore \space & \triangle ABC \cong \triangle PQR && [\text{By SAS criterion}]
\end{aligned}
Hence Proved.