Power of a point P intersects the circle at A and B, the endpoints of the diameter. Their respective products of distances are equal to each other and to the power of point P in that circle This equality is sometimes known as the ""secant-tangent theorem"", ""intersecting chords theorem"", or the ""power-of-a-point theorem"". The power of a point is used in many geometrical definitions and proofs. For example, the radical axis of two given circles is the straight line consisting of points that have equal power to both circles. For each point on this line, there is a unique circle centered on that point
Circle MRT line be operated by SMRT, after the North South line and the East West line. As the name implies, the line is an orbital circle route linking all radial routes leading to the city. It also covers many parts of the Central Area. From Promenade, the line branches into two, with one branch terminating at Dhoby Ghaut, and the other at Marina Bay. The Circle line interchanges with all other Mass Rapid Transit lines within Singapore, such as the North South line and East West line. Plans for the Circle line were laid out in the 1980s, when the then Minister