Question

If one of the four angles formed by two intersecting lines is a right angle, then show that each of the four angles is a right angle.

Answer 1

The given problem can be drawn as :

It is given that

Also,and form a linear pair.

Therefore, their sum must be equal to.

Substituting, above, we get:

Similarly, we can prove that

and

Hence, we have proved that ,If one of the four angles formed by two intersecting lines is a right angle, then show that each of the four angles is a right angle.