File - Mrs. M. Brown
... Therefore, ABC = ½ (110) = 55° To solve z: Since OB, AO and OC are radii, all of the triangles are isosceles. Therefore z = OAC. Since all angles of a triangle add up to 180°, 120 + z + z = 180 2z = 180 – 120 2z = 60 z = 30° ...
... Therefore, ABC = ½ (110) = 55° To solve z: Since OB, AO and OC are radii, all of the triangles are isosceles. Therefore z = OAC. Since all angles of a triangle add up to 180°, 120 + z + z = 180 2z = 180 – 120 2z = 60 z = 30° ...
6-5 Trapezoids and Kites
... How do the angles that share or include a leg in a trapezoid compare to each other? Which theorem helps you reach this conclusion? Since certain angle pairs in a trapezoid are congruent and other angle pairs are supplementary, there are good algebra problems involving the angles of a trapezoid. Exam ...
... How do the angles that share or include a leg in a trapezoid compare to each other? Which theorem helps you reach this conclusion? Since certain angle pairs in a trapezoid are congruent and other angle pairs are supplementary, there are good algebra problems involving the angles of a trapezoid. Exam ...
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.)