Question
ABCD is a quadrilateral such that diagonal AC bisects the angles $\angle\text{A}$ and $\angle\text{C}.$ Prove that AB = AD and CB = CD.

Answer


In $\triangle\text{ABC}$ and $\triangle\text{ADC},$

$\angle\text{BAC}=\angle\text{DAC}$ $\big($AC bisects $\angle\text{A}\big)$

$\text{AC = AC}$ (common)

$\angle\text{BCA}=\angle\text{DCA}$ $\big($AC bisects $\angle\text{C}\big)$

$\therefore\triangle\text{ABC}\cong\triangle\text{ADC}$ (by ASA congruence criterion)

$\Rightarrow\text{AB = AD}$ and $\text{CB = CD}$ (C.P.C.T.)

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

In figure, PQRS is a square and T and U are, respectively, the mid-points of PS and QR. Find the area of $\triangle\text{OTS}$ if PQ = 8cm.

Find the area of a triangle, two sides of which are 8 cm and 11 cm and the perimeter is 32 cm.
Find six rational numbers between 2 and 3.
The following are the marks (out of 100) of 60 students in mathematics:
16, 13, 5, 80, 86, 7, 51, 48, 24, 56, 70, 19, 61, 17, 16, 36, 34, 42, 34, 35, 72, 55, 75, 31, 52, 28,72, 97, 74, 45, 62, 68, 86, 35, 85, 36, 81, 75, 55, 26, 95, 31, 7, 78, 92, 62, 52, 56, 15, 63,25, 36, 54, 44, 47, 27, 72, 17, 4, 30
Construct a grouped frequency distribution table with width 10 of each class starting from 0-9.
It being given that $\sqrt{2}=1.414,\sqrt{3}=1.732,\sqrt{5}=2.236$ and $\sqrt{10}=3.162,$ find the value of three places of decimals, of the following:
$\frac{\sqrt{10}-\sqrt{5}}{\sqrt{2}}$
Factorize the following expressions:
8x2y- x5
Represent geometrically the following numbers on the number line:
$\sqrt{2.3}$
Factorise:
$\frac{1}{3}\text{x}^2-2\text{x}-9$
In figure, ABC is a right angled triangle at A, BCED, ACFG and ABMN are squares on the sides BC, CA and AB respectively. Line segment $\text{AX}\perp\text{DE}$ meets BC at Y. Show that:

$\text{ar}(\text{CYXE})=2\text{ar}(\triangle\text{FCB})$
If x is a positive real number and exponents are rational numbers, simplify
$\Big(\frac{\text{x}^\text{b}}{\text{x}^\text{c}}\Big)^{\text{b+c-a}}\times\Big(\frac{\text{x}^\text{c}}{\text{x}^\text{a}}\Big)^{\text{c+a-b}}\times\Big(\frac{\text{x}^\text{a}}{\text{x}^\text{b}}\Big)^{\text{a+b-c}}.$