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 road was temporarily closed to traffic. On 20 September 2011, a power fault disrupted train services on all 16 stations on the Circle line. The four hours delay left thousands of commuters stranded during rush-hour. It was reported that leaks and a damaged electrical cable along the Circle line were the cause of the disruption. The disruption started at about 5.30 am. Train services were gradually restored from 8am and all services were restored just before 10am. Dakota and Mountbatten stations were the last two to resume operations. Investigations were carried out. It was later found that a faulty cable