proof explanation for one and only one tangent can be drawn at apoint on the circle

Dear Student,

If the P is the ponit on circle, through which tangent is drawn. That means the angle between the tangent and the Line joining PO (O is the center of the circle). will be 90 degree. Now if we slightly change the angle then firstly the angle will not remain 90 degree. Secondly the line will become secant (not tangent).

Thanks.