$CD$ and $GH$ are respectively the bisectors of $\angle ACB$ and $\angle EGF$ such that $D$ and $H$ lie on sides $AB$ and $FE$ of $\Delta ABC$ and $\Delta EFG$ respectively. If $\Delta ABC \sim \Delta FEG,$ show that:
$(i) \frac{CD}{GH} = \frac{AC}{FG}$
$(ii) \Delta DCB \sim \Delta HGE$
$(iii) \Delta DCA \sim \Delta HGF$

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) It is given that $\Delta ABC \sim \Delta FEG$.
Therefore,$\angle A = \angle F, \angle B = \angle E,$ and $\angle ACB = \angle FGE$.
Since $\angle ACB = \angle FGE,$ their bisectors are also equal.
Therefore,$\angle ACD = \angle FGH$ (Angle bisector).
And,$\angle DCB = \angle HGE$ (Angle bisector).
$(i)$ In $\Delta DCA$ and $\Delta HGF$:
$\angle A = \angle F$ (Given)
$\angle ACD = \angle FGH$ (Proved above)
Therefore,$\Delta DCA \sim \Delta HGF$ (By $AA$ similarity criterion).
Since the triangles are similar,the ratio of their corresponding sides is equal:
$\frac{CD}{GH} = \frac{AC}{FG}$.
$(ii)$ In $\Delta DCB$ and $\Delta HGE$:
$\angle DCB = \angle HGE$ (Proved above)
$\angle B = \angle E$ (Given)
Therefore,$\Delta DCB \sim \Delta HGE$ (By $AA$ similarity criterion).
$(iii)$ In $\Delta DCA$ and $\Delta HGF$:
$\angle A = \angle F$ (Given)
$\angle ACD = \angle FGH$ (Proved above)
Therefore,$\Delta DCA \sim \Delta HGF$ (By $AA$ similarity criterion).

Explore More

Similar Questions

$E$ and $F$ are points on the sides $PQ$ and $PR$ respectively of a $\Delta PQR$. For each of the following cases,state whether $EF || QR$. $PQ = 1.28 \, cm, PR = 2.56 \, cm, PE = 0.18 \, cm$ and $PF = 0.36 \, cm$.

Give two different examples of pairs of similar figures.

In the figure,two chords $AB$ and $CD$ intersect each other at the point $P$. Prove that $AP \cdot PB = CP \cdot DP$.

State which pairs of triangles in the figure are similar. Write the similarity criterion used by you for answering the question and also write the pairs of similar triangles in the symbolic form.

In the figure,$\frac{QR}{QS} = \frac{QT}{PR}$ and $\angle 1 = \angle 2$. Show that $\Delta PQS \sim \Delta TQR$.

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