Question

16.Prove that the tangents drawn at the end of a diameter of a circle are
parallel
​

Answer 1

The presence of different amounts of various gases in air doesn't mean that air would be heterogeneous mixture.

Always, mixture of two or more gases is homogenous mixture, irrespective of the amounts of various gases present in the mixture.

Answer 2

Let AB be a diameter of the circle. Two tangents PQ and RS are drawn at points A and B respectively.

Radius drawn to these tangents will be perpendicular to the tangents.

Thus, OA ⊥ RS and OB ⊥ PQ

∠OAR = 90º

∠OAS = 90º

∠OBP = 90º

∠OBQ = 90º

It can be observed that

∠OAR = ∠OBQ (Alternate interior angles)

∠OAS = ∠OBP (Alternate interior angles)

Since alternate interior angles are equal, lines PQ and RS will be parallel .