Mathematics for IGCSE & O level - Circle Theorems (Section 1 - No. 30)
Which theorem is most useful in determining the angles formed by a chord and a tangent at the point of contact?
Angle in the same segment
Alternate Segment Theorem
Angle at the center is twice the angle at the circumference
Opposite angles of a cyclic quadrilateral are supplementary
Paliwanag
The alternate segment theorem directly relates a chord and tangent.