Question
In the given figure, $\text{DB}\perp\text{BC},\text{DE}\perp\text{AB}$ and $\text{AC}\perp\text{BC}.$
Prove that $\frac{\text{BE}}{\text{DE}}=\frac{\text{AC}}{\text{BC}}.$

Answer


In the given figure : $\text{DB}\perp\text{AB},\text{AC}\perp\text{BC}$ and DB || AC
$\therefore\angle\text{DBC}=\angle\text{ACB}$
AB is the transversal
$\therefore\angle\text{DBE}=\angle\text{BAC}$ $\big[\text{Alternate }\angle\text{s}\big]$
In $\triangle\text{DBE}$ and $\triangle\text{ABC}$
$\angle\text{DEB}=\angle\text{ACB}=90^\circ$
$\angle\text{DBE}=\angle\text{BAC}$
$\triangle\text{DBE}\sim\triangle\text{ABC}$ [By AA similarity]
$\Rightarrow\frac{\text{BE}}{\text{DE}}=\frac{\text{AC}}{\text{BC}}$
Hence proved.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Prove that the point A(2, 4), B(2, 6) and $\text{C}(2+\sqrt{3},5)$ are the vertices of an equilateral triangle.
A wire is bent to form a square enclosing an area of $484m^2$​​​​​​​. Using the same wire, a circle is formed. Find the area of the circle.
If the mean of the following distribution is 27, find the value of p.
Class
0-10
10-20
20-30
30-40
40-50
Frequency
8
p
12
13
10
The $17^{\text {th }}$ term of an A.P. is 5 more than twice its $8^{\text {th }}$ term. If the $11^{\text {th }}$ term of the A.P. is 43 . find the $n ^{\text {th }}$ term.
Find the value of k for which the root are real and equal in the following equations:
$4x^2- 2(k + 1)x + (k + 4) = 0$
Prove the following trigonometric identities.
$\Big(\frac{1+\sin\theta-\cos\theta}{1+\sin\theta+\cos\theta}\Big)^2=\frac{1-\cos\theta}{1+\cos\theta}$
While boarding an aeroplane, a passenger got hurt. The pilot showing promptness and concern, made arrangements to hospitalise the injured and so the plane started late by $30$ minutes to reach the destination, $1500\ km$ away in time, the pilot increased the speed by $100\ km/hr$. Find the original speed/hour of the plane.
The cost of 2kg of apples and 1kg of grapes on a day was found to be Rs. 160. After a month, the cost of 4kg of apples and 2kg of grapes is Rs. 300 Represent the situation algebraically and geometrically.
Draw circles with centres A, B and C each of radius 3 cm, such that each circle touches the other two circles.
Solve : $\frac{5}{x-1}+\frac{1}{y-2}=2 ; \frac{6}{x-1}-\frac{3}{y-2}=1$