Mathematics · Geometry

Which of the following geometric statements concerning circles are correct? 1. The perpendicular drawn from the centre of a circle to a chord bisects the chord. 2. Two circles are congruent to each other if they have equal radii. 3. The tangent at any point of a circle is perpendicular to the radius drawn through the point of contact. 4. All secants drawn from a single point outside a circle have equal lengths.