In $\Delta PQR$,$m\angle Q = 90^{\circ}$ and $\overline{PM}$ is a median. Prove that $PR^{2} = PM^{2} + 3RM^{2}$.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) $1$. In $\Delta PQR$,$\angle Q = 90^{\circ}$. By Pythagoras theorem,$PR^{2} = PQ^{2} + QR^{2}$.
$2$. Since $\overline{PM}$ is a median to side $\overline{QR}$,$M$ is the midpoint of $\overline{QR}$. Therefore,$QM = RM = \frac{1}{2} QR$,which implies $QR = 2RM$.
$3$. In right-angled $\Delta PQM$,by Pythagoras theorem,$PM^{2} = PQ^{2} + QM^{2}$. Thus,$PQ^{2} = PM^{2} - QM^{2}$.
$4$. Substitute $PQ^{2} = PM^{2} - QM^{2}$ and $QR = 2RM$ into the first equation: $PR^{2} = (PM^{2} - QM^{2}) + (2RM)^{2}$.
$5$. Since $QM = RM$,substitute $QM$ with $RM$: $PR^{2} = PM^{2} - RM^{2} + 4RM^{2}$.
$6$. Simplifying the expression,we get $PR^{2} = PM^{2} + 3RM^{2}$. Hence proved.

Explore More

Similar Questions

In $\Delta PQR$,$m\angle Q = 90^\circ$. If $PQ = 8$ and $QR = 15$,then $PR = \ldots$

In the figure,$A, B$ and $C$ are points on $OP, OQ$ and $OR$ respectively such that $AB \parallel PQ$ and $AC \parallel PR$. Show that $BC \parallel QR$.

Difficult
View Solution

$A$ line drawn parallel to $\overline{YZ}$ in the plane of $\Delta XYZ$ passes through the midpoint of $\overline{XY}$. Prove that this line bisects $\overline{XZ}$.

In $\Delta ABC$,$\overline{AD}$ and $\overline{BE}$ are medians. Line $m$ through $D$ and parallel to $\overline{BE}$ intersects $\overline{AC}$ at $K$. If $EK = 2.5$,then $AC = \ldots$

$ABC$ is an equilateral triangle of side $2a$. Find each of its altitudes.

Difficult
View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo