Question

find out the sum of four angles of e quadrilateral using the angles sum property of triangle.​

Answer 1

Step-by-step explanation:

Angle sum property of quadrilateral =360

Let the quadrilateral =ABCD

The diagnol divide quadrilateral into two similar triangle triangles are ABC AND ADC

So area of triangle =1/2quad

ABC=1/2×360

Angle sum property of triangle ABC=180

Answer 2

Answer:

Let the quadrilateral be a rectangle

if we join its diagonals , they bisects the angles at each corner since its diagonals are eqal and bisect each other so by angle opposite to eqal sides it can be proved

so, if we join one of its diagonals we get 2 triangles in which one angle is 90 whereas other two angles are equal in each of them .

so , 90 +a+b=180

a+a =90

a=45

similarly in other triangle

x+y=90

x=45

area of the quadrilateral =area of the two triangles

=180+180

=360 degrees