In a rhombus $ABCD$,prove that $AC^{2} + BD^{2} = 4AB^{2}$.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) Let the diagonals $AC$ and $BD$ of the rhombus $ABCD$ intersect at point $O$.
Since the diagonals of a rhombus bisect each other at right angles $(90^{\circ})$,we have $AO = OC = \frac{AC}{2}$ and $BO = OD = \frac{BD}{2}$.
In the right-angled triangle $\triangle AOB$,by the Pythagoras theorem:
$AB^{2} = AO^{2} + BO^{2}$
Substitute the values of $AO$ and $BO$:
$AB^{2} = (\frac{AC}{2})^{2} + (\frac{BD}{2})^{2}$
$AB^{2} = \frac{AC^{2}}{4} + \frac{BD^{2}}{4}$
$AB^{2} = \frac{AC^{2} + BD^{2}}{4}$
Multiplying both sides by $4$,we get:
$4AB^{2} = AC^{2} + BD^{2}$
Hence,it is proved that $AC^{2} + BD^{2} = 4AB^{2}$.

Explore More

Similar Questions

In $\Delta ABC$,$m\angle B = 90^{\circ}$ and $\overline{BM}$ is a median. If $AB = 15$ and $BM = 12.5$,find $BC$.

$\Delta ABC \sim \Delta PQR$ for the correspondence $ABC \leftrightarrow RPQ$. If $m \angle A + m \angle C = m \angle B$,then in $\Delta PQR$,$\ldots \ldots \ldots$ is a right angle.

In $\Delta ABC$,the bisector of $\angle A$ intersects $\overline{BC}$ at $D$. If $AB = 10$,$BC = 6$,and $AC = 14$,find $BD$ and $DC$.

In $\Delta ABC$,$\overline{AD}$ is a median. The bisectors of $\angle ADB$ and $\angle ADC$ intersect $\overline{AB}$ and $\overline{AC}$ at $E$ and $F$ respectively. Prove that $\overline{EF} \parallel \overline{BC}$.

In $\Delta ABC$,$m \angle B = 90^{\circ}$ and $\overline{BM}$ is an altitude. If $BM = 12$ and $AM = 9$,then $AC = \ldots$

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