D and E are points on the sides AB and AC respectively of a $\triangle\text{ABC}$ such that DE || BC:
If AD = 3.6cm, AB = 10cm and AE = 4.5cm, find EC and AC.
Download our app for free and get started
In $\triangle\text{ABC},$ it is given that DE || BC.
Applying Thales' theorem, we get:
$\frac{\text{AD}}{\text{DB}}=\frac{\text{AE}}{\text{EC}}$
$\therefore\text{AD}=3.6,\text{AB}=10\text{cm},\text{AE}=4.5\text{cm}$
$\therefore\text{DB}=10-3.6=6.4\text{cm}$
or, $\frac{3.6}{6.4}=\frac{4.5}{\text{EC}}$
or, $\text{EC}=\frac{6.4\times4.5}{3.6}$
or, $\text{EC}=8\text{cm}$
Thus, $\text{AC}=\text{AE}+\text{EC}$
$=4.5 +8=12.5\text{cm}$
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Two triangles DEF and GHK are such that $\angle\text{D}=48^\circ$ and $\angle\text{H}=57^\circ.$ If $\triangle\text{DEF}\sim\triangle\text{GHK}$ then find the measure of $\angle\text{F}.$