Question

The sides BA and DC of a quadrilateral ABCD is produced.Prove that a+b=x+y

Answer 1

the regular quadrilateral ABCD
AB = a
BC= b
CD= x
AD= y
for any regular quadrilateral like rectangle
whose opposite sides are equal
a=x (i)
b=y (ii)
from i and ii
a+b = x+y

Answer 2

Answer:

Step-by-step explanation:

In triangle BDC:

angle A = angle2+angle4.......(1)

Exterior angle theorem

In triangle ADB:

Angle B = angle 1+3....(2)

Adding eq (1) and (2) we get

Angles:A+B =1+2+3+4

A+B=X+Y