The angle between a tangent and a chord through the point of contact is equal to the angle in the alternate segment
(alternate segment theorem)
The sequare of the length of the tangement from an external point is equal to the product of the intercepts of the secant passing through this point
(tangent-secant theorem)
The exterior angle at a vertex of a cyclic quadrilateral is equal to the interior opposite angle in a circle
(ext. angles = interior opp. <'s)
(alternate segment theorem)
The sequare of the length of the tangement from an external point is equal to the product of the intercepts of the secant passing through this point
(tangent-secant theorem)
The exterior angle at a vertex of a cyclic quadrilateral is equal to the interior opposite angle in a circle
(ext. angles = interior opp. <'s)