Geometry 2 | P a g e
41. Rectangle – parallelogram with a right angle.
42. Rhombus – parallelogram with consecutive sides congruent.
43. Square – all sides congruent and all four right angles.
44. Trapezoid – quadrilateral with exactly one pair of opposite sides parallel.
45. Ratio – comparison of two numbers by division.
46. Proportion – equation that states two ratios are equal.
47. Pythagorean Theorem – in a right triangle, the sum of the squares of the legs is equal to the square of the
hypotenuse
48. Circle – the set of points in a plane that are equidistant from a fixed point called the center.
49. Radius – segment whose endpoints are the center of the circle and a point on the circle.
50. Chord – segment that connects two points on the circle.
51. Diameter – chord that passes through the center of the circle.
52. Secant – line that intersects a circle in two points.
53. Tangent – line in the plane of the circle that intersects the circle in one point.
54. Concentric circles – two or more circles in the same plane with the same center.
55. Congruent circles – circles that have congruent radii.
56. Sphere – set of points in space a given distance from a given point called the center.
57. Arc – consists of two points and the continuous part of a circle between them.
58. Semi-circle – arc whose endpoints are the endpoints of a diameter.
59. Minor arc – arc whose measure is less than a semi-circle (180 degree).
60. Major arc – arc whose measure is greater than a semi-circle (180 degrees).
61. Central angle of a circle – angle whose vertex is the center of the circle and whose rays are radii of the
circle.
62. Congruent arcs – arcs with equal measure in the same circle or in congruent circles.
63. Inscribed angles – angle whose vertex is on the circle and whose sides are chords of the circle.
64. Bases – congruent polygons lying in parallel planes.
65. Altitude – segment joining the two base planes and perpendicular to both.
66. Lateral faces – faces of a prism that are not its bases.
67. Lateral edges – intersection of adjacent lateral faces form lateral edges.
68. Lateral area – sum of the area of its lateral faces.
69. Surface area – sum of the area of all its faces.
70. Volume – number of cubic units contained in a solid.
71. Right Prism – is a prism whose lateral faces are rectangles.
72. Oblique prism – is a prism whose lateral faces are parallelograms.
73. Cube – is a prism where all sides are squares.
74. Triangular prism – is a prism whose parallel faces (the bases) are congruent triangles.
75. Cylinder – has two congruent circular bases in parallel planes.
76. Cone – has a vertex and a circular base.
77. Line of symmetry – divides a figure into two congruent halves that reflect each other.
78. Perimeter – of a polygon is the distance around the polygon.
79. Area – of any surface is the number of square units required to cover the surface.
80. Volume – of a 3-dimensional figure is the number of cubic units contained in the solid.
81. Circumference – the distance around a circle.
82. Conditional statement – a statement that can be written in an if-then form.
83. Hypothesis – in a conditional statement the statement that immediately follows the word ‘if’.
84. Conclusion – in a conditional statement the statement that immediately follows the word ‘then’.
85. Converse – the statement formed by exchanging the hypothesis and the conclusion of a conditional
statement.
86. Inverse – the statement formed by negating both the hypothesis and the conclusion of a conditional
statement.
87. Contrapositive – the statement formed by negating both the hypothesis and conclusion of the converse of
a conditional statement.
88. Bi-conditional – the conjunction of a conditional statement and its converse.