Secant line point a "tangent line" and in no points an "exterior line". A "chord" of a circle is the line segment that joins two distinct points of the circle. A chord is therefore contained in a unique secant line and each secant line determines a unique chord. In rigorous modern treatments of plane geometry, results that seem obvious and were assumed (without statement) by Euclid in his treatment, are usually proved. For instance, "Theorem (Elementary Circular Continuity)": If formula_1 is a circle and formula_2 a line that contains a point that is inside formula_1 and a point that is outside of
City Circle Line City Circle Line The City Circle Line () or M3 is a future loop line of the Copenhagen Metro. It has been claimed by COWI A/S that the City Circle Line is the largest construction project to have taken place in Copenhagen during the last 400 years. Upon its completion, the network's total length shall be 43km and have 17 stations. Its completion has been anticipated to occur around the summer of 2019. Plans for its construction were approved by the Danish Parliament on 1 June 2007. Preferred bidders were announced during November 2010. The total cost was estimated at