Question

if two lines intersect each other at point then prove That their vertically opposite Angeles are equal

Answer 1

In the given picture,
angle 1 + angle 2 = 180 .....(1)
angle 1 + angle 4 = 180 ......(2)
angle 2 + angle 3 = 180.....(3)
angle 3 + angle 4 = 180.....(4)

Comparing all 4 equations,
we get
angle 1 = angle 3 and angle 2 = angle 4