Non-Euclidean Geometry
... m and l meet on that side of the line n on which the angles 1 and 2 lie. If the sum is 180° then m and l are parallel” ...
... m and l meet on that side of the line n on which the angles 1 and 2 lie. If the sum is 180° then m and l are parallel” ...
Geometry Chapter 1 – The Basics of Geometry
... Sketch intersections of lines & planes. Find perimeter, circumference, and area of common plane figures. - Visualize the basic elements of geometry and the ways they can intersect. ...
... Sketch intersections of lines & planes. Find perimeter, circumference, and area of common plane figures. - Visualize the basic elements of geometry and the ways they can intersect. ...
History of geometry
Geometry (from the Ancient Greek: γεωμετρία; geo- ""earth"", -metron ""measurement"") arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers (arithmetic).Classic geometry was focused in compass and straightedge constructions. Geometry was revolutionized by Euclid, who introduced mathematical rigor and the axiomatic method still in use today. His book, The Elements is widely considered the most influential textbook of all time, and was known to all educated people in the West until the middle of the 20th century.In modern times, geometric concepts have been generalized to a high level of abstraction and complexity, and have been subjected to the methods of calculus and abstract algebra, so that many modern branches of the field are barely recognizable as the descendants of early geometry. (See Areas of mathematics and Algebraic geometry.)