Term | Definition |
1. Adjacent Angles | Two angles are Adjacent if they have a common side and a common vertex (corner point), and don't overlap |
2. Alternate Interior Angles | When two lines are crossed by another line (which is called the Transversal), the pairs of angles on opposite sides of the transversal but inside the two lines |
3. Angle of Depression | the angle below a horizontal |
4. Angle of Elevation | the angle above a horizontal |
5. Apothem | a line from the center of a regular polygon at right angles to any of its sides |
6. Arc | a part of the circumference of a circle or other curve |
7. Intersection | a point or line common to lines or surfaces that intersect |
8. Area of Triangle | 1/2 b*h |
9. Area of Equilateral Triangle | side^2*square root of 3 divided by 4 |
10. Midpoint | the exact middle point |
11. Inductive Reasoning | is reasoning in which the premises seek to supply strong evidence for (not absolute proof of) the truth of the conclusion |
12. Area of Circle | 3.14r^2 |
13. Area of Regular Hexagon | 3*square root of 3/2a^2 |
14. Area of Trapezoid | h(b1 + b2)/2 |
15. Area of Parallelogram | b*h |
16. Biconditional | In logic, a biconditional is a compound statement formed by combining two conditionals under "and" |
17. Bisector | a bisector divides the octave approximately in half |
18. Deductive Reasoning | a logical process in which a conclusion is based on the concordance of multiple premises that are generally assumed to be true |
19. Central Angle | an angle whose apex (vertex) is the center O of a circle |
20. Centroid | the center of mass of a geometric object of uniform density |
21. Chord | A straight line connecting two points on a curve |
22. Volume of Pyramid/Cone | Area of base*H/3 |
23. Space | the dimensions of height, depth, and width within which all things exist and move |
24. Point | A point specifies only location; it has no length, width, or depth |
25. Line | It continues forever in two directions (so it has infinite length), but it has no width at all |
26. Postulate | Postulate is a true statement, which does not require to be proved |
27. Circle | a round plane figure whose boundary (the circumference) consists of points equidistant from a fixed point (the center) |
28. Counterexample | an example that refutes an assertion or claim |
29. Circumference | the enclosing boundary of a curved geometric figure, esp. a circle |
30. Circumscribed | draw (a figure) around another, touching it at points but not cutting it |
31. Concentric Circles | The region of the plane between two concentric circles is an annulus, and analogously the region of space between two concentric spheres is a spherical shell |
32. Cone | a solid or hollow object that tapers from a circular or roughly circular base to a point |
33. Conjecture | a statement that is believed to be true but not yet proved |
34. Consecutive | one after another |
35. Complementary Angles | either of two angles whose sum is 90° |
36. Convex Polygon | Every internal angle is less than or equal to 180 degrees. Every line segment between two vertices remains inside or on the boundary of the polygon |
37. Concave Polygon | A concave polygon will always have an interior angle with a measure that is greater than 180 degrees |
38. Supplementary Angles | either of two angles whose sum is 180° |
39. Corollary | a proposition that follows from (and is often appended to) one already proved |
40. Corresponding Parts | Angles that have the same relative positions in geometric figures |
41. Alternate Exterior Angles | , the pairs of angles on opposite sides of the transversal but outside the two lines |
42. Corresponding Angles | the angles that occupy the same relative position at each intersection where a straight line crosses two others. If the two lines are parallel, the corresponding angles are equal |
43. Cosine | the trigonometric function that is equal to the ratio of the side adjacent to an acute angle (in a right-angled triangle) to the hypotenuse |
44. Cross Section | a surface or shape that is or would be exposed by making a straight cut through something, esp. at right angles to an axis |
45. Cylinder | a solid geometric figure with straight parallel sides and a circular or oval section |
46. Dilation | enlarging or shrinking of a shape |
47. Exterior Angle of Polygon | is an angle formed by one side of a simple, closed polygon and a line extended from an adjacent side |
48. Triangle Inequality Thm. | the sum of the lengths of any two sides must be greater than or equal to the length of the remaining side |
49. Segment | a part of a figure cut off by a line or plane intersecting it, in particula |
50. Ray | never ending line with a point and an arrow going in one direction |
51. Collinear | points lying in the same straight line |
52. Theorem | a general proposition not self-evident but proved by a chain of reasoning; a truth established by means of accepted truths |
53. Geometric Mean | the central number in a geometric progression (e.g., 9 in 3, 9, 27 ), also calculable as the n th root of a product of n numbers |
54. Converse | the central number in a geometric progression (e.g., 9 in 3, 9, 27 ), also calculable as the n th root of a product of n numbers |
55. Inscribed Angle | An inscribed angle is an angle formed by two chords in a circle which have a common endpoint |
56. Inverse | the opposite |
57. Contrapostive | which says that a conditional statement is logically equivalent to its contrapositive |
58. Line of Symmetry | is the imaginary line where you could fold the image and have both halves match exactly |
59. Conditional | A conditional statement, symbolized by pq, is an if-then statement in which p is a hypothesis and q is a conclusion |
60. Orthographic Drawings | a means of representing a three-dimensional object in two dimensions |
61. Parallelogram | a four-sided plane rectilinear figure with opposite sides parallel |
62. Perimeter | the continuous line forming the boundary of a closed geometric figure |
63. Perpendicular Bisector | a line that passes through the midpoint of a given segment |
64. Platonic Solids | tetrahedron, hexahedron, octahedron, dodecahedron, icosahedron |
65. Scalene | having sides unequal in length |
66. Prism | a solid geometric figure whose two end faces are similar, equal, and parallel rectilinear figures, and whose sides are parallelograms |
67. Pyramid | a monumental structure with a square or triangular base and sloping sides that meet in a point at the top |
68. Linear Pair | two angles add up to 180 |
69. Lateral Area | area of the faces only |
70. Radius | the line from the center of the circle to the edge of the circle |
71. Diameter | a line from the edge of the circle to the other edge of the circle, crosses through the center |
72. Reflection | flipping |
73. Heptagon | 7 sided shape |
74. Vertical Angles | are non-adjacent angles formed by a pair of intersecting lines |
75. Parallel | lines that go in the same direction and never touch |
76. Perpendicular | lines that cross each other and go on forever |
77. Angle | lines for this when they cross |
78. Midsegment | the middle of a segment |
79. Octagon | 8 sided shape |
80. Regular Polygon | a polygon that is equiangular (all angles are equal in measure) and equilateral (all sides have the same length) |
81. Pentagon | 5 sided shape |
82. Rotation | turn |
83. Altitude | a line segment connecting a vertex to the line containing the opposite side and perpendicular to that side |
84. Median | a segment connecting any vertex of a triangle to the midpoint of the opposite side |
85. Nonagon | 9 sided shape |
86. Decagon | 10 sided shape |
87. Dodecagon | a plane figure with twelve sides |
88. Secant Line | a straight line joining two points on a function |
89. Sine | trig function |
90. Tangent | trig function |
91. Tangent to a Circle | a line touching the outside of the circle |
92. Similar Polygon | same shape just different side lenghts |
93. Slope | 3/5 |
94. Slope Intercept Form | y=mx+b |
95. Special Right Triangle | 30,60,90 or 45,45,90 |
96. Sphere | 3 dimensional circle |
97. Surface Area | how much the shape can hold |
98. Tessellate | arrange shapes so there is no gaps |
99. Transformation | Moving a shape so that it is in a different position, but still has the same size, area, angles and line lengths |
100. Volume of Cylinder/Prism | area of base*h |
101. Acute Angle | angle less than 90 |
102. Obtuse Angle | angle more than 90 |
103. Straight Angle | angle equal to 180 |
104. Skew Lines | lines that are not parallel nor perpendicular |