In the figure,$OD$ is perpendicular to chord $AB$ of a circle whose centre is $O.$ If $BC$ is a diameter,prove that $CA = 2OD$.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) We have a circle with centre $O$. $BC$ is a diameter and $AB$ is a chord such that $OD \perp AB$. Join $AC$.
The perpendicular from the centre of a circle to a chord bisects the chord. Therefore,$D$ is the midpoint of $AB$.
Since $O$ is the centre of the circle,$O$ is the midpoint of the diameter $BC$.
In $\triangle ABC$,$O$ is the midpoint of $BC$ and $D$ is the midpoint of $AB$. Therefore,$OD$ is the line segment joining the midpoints of two sides of $\triangle ABC$.
By the Midpoint Theorem,the line segment joining the midpoints of two sides of a triangle is parallel to the third side and is half of it.
Therefore,$OD \parallel CA$ and $OD = \frac{1}{2} CA$.
Hence,$CA = 2OD$.

Explore More

Similar Questions

$AB$ and $AC$ are two chords of a circle of radius $r$ such that $AB = 2 AC$. If $p$ and $q$ are the distances of $AB$ and $AC$ from the centre,prove that $4 q^{2} = p^{2} + 3 r^{2}$.

Difficult
View Solution

In a cyclic quadrilateral $PQRS$,$\angle P = \angle R + 50^{\circ}$. Find $\angle P$ and $\angle R$.

$AB$ and $AC$ are two chords of a circle with centre $P$. If the bisector of $\angle BAC$ passes through the centre $P$,prove that $AB = AC$.

If the perpendicular bisector of a chord $AB$ of a circle $PXAQBY$ intersects the circle at $P$ and $Q$,prove that arc $PXA \cong$ arc $PYB$.

In a circle with centre $O$,$PQ$ and $XY$ are chords. If $\angle POQ = 120^{\circ}$,$\angle OXY = 30^{\circ}$ and $XY = 8 \, cm$,then $PQ$ is ........... $cm$.

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