In Fig. 6.16, if x + y = w + z, then prove that AOB is a line.
It is given in the question that:
x + y = w + z
To prove,
AOB is a line or x + y = 180o (Linear pair)
Now, according to the question,
x + y + w + z = 360o (Angles at a point)
(x + y) + (w + z) = 360o
(x + y) + (x + y) = 360o (Given, x + y = w + z)
2 (x + y) = 360o
(x + y) = 180o
Therefore, x + y makes a linear pair.
And, AOB is a straight line