Dunkirk - Student Encyclopedia (Ages 11 and up) An important commercial seaport, Dunkirk lies in the extreme north of France on the Strait of Dover. In the evacuation of Dunkirk, one of the great actions of World War II, the town was demolished, but much of it had been rebuilt by 1953.
A line segment is a part of a line that is bounded by two distinct end points and contains every point on the line between its end points. Depending on how the line segment is defined, either of the two end points may or may not be part of the line segment.
A polygon in hyperbolic geometry is a sequence of points and geodesic segments joining those points. The geodesic segments are called the sides of the polygon. A triangle in hyperbolic geometry is a polygon with three sides, a quadrilateral is a polygon with four sides, and so on, as in Euclidean geometry. Here are some triangles in hyperbolic space: From these pictures, you can see that: The sum of the angles in any hyperbolic triangle is less than 180Â°.