click below
click below
Normal Size Small Size show me how
Geometry Terms
| Question | Answer |
|---|---|
| Point | No dimension, represents a precise location, symbolized with a dot and a capital letter. |
| Line | One dimension (length). A straight path that extends infinitely in both directions. Two points determine a line. |
| Segment | A part of a line between two endpoints. A finite length. |
| Plane | A two dimensional (length and width) surface that extends infinitely in all directions. 3 non-collinear points determine a plane. |
| Collinear | Three or more points on the same line. Co (together) Linear (line). |
| Non-Collinear | Three or more points that are NOT on the same line. You know that 3 points are non collinear when you cannot draw one line that contains all three of those points. |
| Coplanar | Points that lie on the same plane. |
| Compass | Geometric tool used to draw a circle or part of a circle known as an arc. |
| Straightedge | A tool used to draw straight lines. |
| Congruent | Identical. Exactly the same shape and same size. |
| Distance | The length of the segment between two points. |
| Intersection | A point or set of points common to two or more geometric figures. The intersection of two lines is a point. The intersection of two planes is a line. |
| Linear Pair | A pair of angles (two) that form a straight line. These are adjacent and add up to 180 degrees. |
| Adjacent | Next to one another. Two angles are adjacent when they share a common vertex and a common side. |
| Vertex | A common endpoint. The vertex of an angle is where the two sides of the angle converge or meet. |
| Midpoint | The point exactly halfway between the endpoints of a segment. |
| Angle | Two rays with a common vertex form an angle measured in degrees. |
| Acute Angle | An angle that measures between 0 and 90 degrees. |
| Obtuse Angle | An angle that measures between 90 and 180 degrees. |
| Straight Angle | An angle that measures exactly 180 degrees. |
| Construction Mark | A mark created using a compass. An arc is another name for a construction mark. |
| Radius | Constant distance from the center of a circle to a point on the circle. |
| Right Angle | An angle that measures exactly 90 degrees. |
| Supplementary Angles | Two angles whose sum is 180 degrees. |
| Complementary Angles | Two angles whose sum is 90 degrees. |
| Proof | A logical argument in which each statement you make is supported by a reason that is accepted as true. |
| Parallel Lines | Two lines that never intersect. There is always 180 degrees between them. |
| Perpendicular | Forms a right angle. |
| Equilateral | Having equal side lengths. |
| Equiangular | Having equal angles. |
| Right Triangle | A triangle that contains a right angle |
| Triangle | 3 sided Polygon. Interior angles always sum to 180 degrees. |
| Isosceles Triangle | Triangle with two congruent Legs and two congruent base angles. |
| Equilateral Triangle | Triangle with 3 congruent sides and angles. |
| Corresponding parts | Matching parts of congruent figures. |
| Pythagorean Theorem | A group of three whole numbers that satisfies the equation a^2 + b^2 = c^2, where c is the greatest number. |
| Hypotenuse | The largest side of a right triangle. This side is directly 0pposite the right angle. |
| Equidistant | The same distance. |
| Perpendicular Bisector | A line that is perpendicular (forms right angle) and passes through the midpoint of a segment. Any point on a perpendicular bisector is always equidistant from the two points in which is being bisected. |
| Bisector | Cuts exactly into two congruent parts. |
| Angle Addition | Part + Part = Whole. The Whole is the sum of its parts. Two adjacent angles that combine to form a larger angle. |
| Segment Addition | Part + Part = Whole. The Whole is the sum of its parts. Two segments that combine to form a larger segment. |