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Ultimate Geometry (Terms, Postulates, Theorems, etc.) Flashcards

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44424072pointa location (undefined term)0
44424073planea flat surface made up of points; has no depth and extends indefinitely in all directions (undefined term)1
44424074linemade up of points and has no thickness or width (undefined term)2
44424075collinear pointspoints on the same line3
44424076axioms/postulatesstatements that are accepted without proofs4
44424077theoremsstatements that can be proven5
44424078coplanarpoints that lie on the same plane6
44424079spacea boundless, three-dimensional set of all points; can contain lines and planes7
44424080congruent line segmentstwo line segments with equal lengths8
44424081raya type of line that has one endpoint9
44424082opposite raystwo rays are opposite to each other iff they have the same endpoint and they are collinear10
44424083angletwo rays that share an endpoint11
44424084angle bisectorrays, line segments, or lines that divide and angle into two equal parts12
44424085complimentary anglestwo angles whose measures add up to 90°13
44424086supplementary anglestwo angles whose measures add up to 180°14
4442408790-xcompliment of an angle15
44424088180-xsupplement of an angle16
44424089adjacent anglestwo angles that share a side, share a vertex, and have no common interior point17
44424090linear pairsa pair of adjacent angles whose non-common sides are opposite rays18
44424091regular polygona polygon where all the sides and angles are congruent19
44424092triangle3 sides20
44424093quadrilateral4 sides21
44424094pentagon5 sides22
44424095hexagon6 sides23
44424096heptagon7 sides24
44424097octagon8 sides25
44424098nonagon9 sides26
44424099decagon10 sides27
44424100hendecagon11 sides28
44424101dodecagon12 sides29
44424102conditional statementa statement that can be written in if-then form30
44424103conversethe statement formed by exchanging the hypothesis and conclusion of a conditional statement31
44424104inversethe statement formed by negating both the hypothesis and conclusion of a conditional statement32
44424105contrapositivethe statement formed by negating both the hypothesis and conclusion of the converse of a conditional statement33
44424106symmetric propertyif a=b then b=a34
44424107skew linesif two lines are not on the same plane, they cannot intersect35
44424108transversala line that intersects two (or more) lines at two different points36
44424109corresponding angles (postulate)if two parallel lines are cut by a transversal, then the corresponding angles are congruent37
44424110converse of corresponding angles (postulate)if corresponding angles are congruent, then the lines are parallel38
44424111scalenetype of triangle where all sides are different lengths39
44424112isoscelestype of triangle where at least two sides have equal lengths40
44424113equilateraltype of triangle where all sides are equal in length41
44424114acutetype of triangle where all angles are acute42
44424115obtusetype of triangle that contains exactly one obtuse angle43
44424116righttype of triangle that contains exactly one right angle44
44424117angle sum theoremgiven a triangle, the sum of the measures of the interior angles is 180°45
44424118alternate interior angle (theorem)if two parallel lines are cut by a transversal, then each pair of alternate interior angles is congruent46
44424119consecutive interior angle (theorem)if two parallel lines are cut by a transversal, then each pair of consecutive interior angles is supplementary47
44424120alternate exterior angle (theorem)if two parallel lines are cut by a transversal, then each pair of alternate exterior angles is congruent48
44424121third angle theoremif two angles of one triangle are congruent to two angles of a second triangle, then the third angles of the triangles are congruent49
44424122exterior angle theoremthe measure of an exterior angle of a triangle is equal to the sum of the measures of the two remote interior angles50
44424123sssif the sides of one triangle are congruent to the sides of a second triangle, then the triangles are congruent51
44424124sasif two sides and the included angle of one triangle are congruent to two sides and the included angle another triangle, then the triangles are congruent52
44424125asaif two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, then the two triangles are congruent53
44424126aasif two angles and a non-included side of one triangle are congruent to the corresponding two angles and side of a second triangle, then the two triangles are congruent54
44424127HLif the hypotenuse and a leg of one right triangle are congruent to the hypotenuse and corresponding leg of another right triangle, then the triangles are congruent55
44424128isosceles triangle theoremif two sides of a triangle are congruent, then the angles opposite those sides are congruent56
44424129diagonala line segment that connects two non-adjacent vertices57
44424130CPCTCcorresponding parts of congruent triangles are congruent58
44424131perpendicular bisector (of a line segment)a line that cuts through another line segment at its midpoint and bisects it at a 90° angle59
44424132circumcenterpoint of concurrency for perpendicular bisectors; equidistant from the vertices60
44424133centroidpoint of concurrency for medians; 1/3 of the whole61
44424134incenterpoint of concurrency for angle bisectors; equidistant from each side62
44424135orthocenterpoint of concurrency for altitudes63
44424136right trianglein what type of triangle is the orthocenter a vertex?64
44424137equilateral trianglein what type of triangle is the orthocenter and circumcenter the same?65
44424138neverin what type of triangle is the centroid outside of the triangle?66
44424139triangle inequality theoremin a triangle, the sum of the measures of two sides is greater than the measure of the third side67
44424140hinge theoremif two sides of one triangle are congruent to two sides of another triangle and the included angle in the first triangle is greater than the included angle in the second triangle, then the remaining side of the first triangle is greater than the remaining side of the second triangle68
44424141converse of hinge theoremif two sides of one triangle are congruent to two sides of another triangle and the third side of the first triangle is greater than the third side of the second triangle, then the angle opposite the third side in the first triangle is greater than the angles opposite the third side in the second triangle69

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