line segment the part of a line between (and including) two points. The geometric notation for the line segment joining points A and B is A B . The notation A B is used both to refer to the segment itself and to its length. major arc an arc greater than or equal to 180° midpoint the point at the exact middle of a line segment minor arc an arc less than or equal to 180° obtuse angle an angle that measures greater than 90° obtuse triangle a triangle with an angle that measures greater than 90° ordered pair a location of a point on the coordinate plane in the form of ( x,y ). The x represents the location of the point on the horizontal x -axis, and the y represents the location of the point on the vertical y -axis. – G E O M E T R Y R E V I E W – 9 6
origin coordinate point (0,0): the point on a coordinate plane at which the x -axis and y -axis intersect parallel lines two lines in a plane that do not intersect. Parallel lines are marked by a symbol ||. parallelogram a quadrilateral with two pairs of parallel sides perimeter the distance around a figure perpendicular lines
