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        | A point specifies only location; it has no length, width, or depth. We usually represent a point with a dot on paper, but the dot we make has some dimension, while a true point has dimension 0. |  | 
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        | A line has only one dimension: length. It continues forever in two directions (so it has infinite length), but it has no width at all. A line connects two points via the shortest path, and then continues on in both directions. |  | 
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        | A plane is a flat, two-dimensional object. We often represent a plane by a piece of paper, a blackboard, or the top of a desk. In fact, none of these is actually a plane, because a plane must continue infinitely in all directions and have no thickness at all. A plane can be defined by two intersecting lines or by three non-collinear points. |  | 
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        | A line segment is a part of a line that is bounded by two end points, and contains every point on the line between its end points. |  | 
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        | A ray can be thought of as a half a line. It has a point on one end, and it extends infinitely in the other direction. |  | 
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        | An angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle. |  | 
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        | A way of measuring the size of angles in which a complete rotation has a measure of 360 degrees |  | 
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        | Two figures are congruent if they have the same shape and size. |  | 
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        | Biconditional statements, or “if and only if” statements, are reversible. They are written as P↔Q and read as “if and only if”. |  | 
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        | An example that is used to disprove a statement. |  | 
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        | A right angle is an internal angle which is equal to 90° |  | 
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        | An Acute Angle is less than 90° |  | 
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        | An Obtuse Angle is more than 90° but less than 180° |  | 
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        | Is the middle point of a line segment. |  | 
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        | Is the line or line segment that divides the angle into two equal parts. |  | 
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        | Remain the same distance apart over their entire length. No matter how far you extend them, they will never meet. |  | 
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        | Intersect to form a right or 90 degree angle. |  | 
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        | Two angles that add up to 90 degrees |  | 
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        | Two Angles are Supplementary if they add up to 180 degrees. |  | 
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        | Are the angles opposite each other when two lines cross |  | 
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        | The two supplementary adjacent angles formed by two intersecting lines |  | 
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        | Is a closed figure made by connecting line segments, where each line segment end connects to only one end of two other line segments. |  | 
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        | A polygon with three corners or vertices and three sides or edges which are line segments. |  | 
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        | Is a polygon with four sides (or 'edges') and four vertices or corners. |  | 
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        | A polygon with six edges and six vertices. |  | 
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        | A polygon with five sides. |  | 
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        | Consecutive Vertices[image] |  | Definition 
 
        | Endpoints of a single side of a polygon |  | 
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        | Consecutive Angles[image] |  | Definition 
 
        | When two lines are crossed by another line |  | 
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        | Consecutive Sides [image] |  | Definition 
 
        | Sides of a polygon that share an endpoint |  | 
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        | Is a path that surrounds an area. |  | 
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        | Is a line joining two nonconsecutive vertices of a polygon or polyhedron. |  | 
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        | All sides have the same length. |  | 
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        | Is a polygon which is equiangular and equilateral |  | 
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        | Is triangle with an angle of 90°  degrees |  | 
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        | A triangle that has all angles less than 90° |  | 
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        | A triangle that has an angle greater than 90° |  | 
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        | A triangle with all sides of different lengths.   No sides are equal and no angles are equal |  | 
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        | Isosceles Triangle [image] |  | Definition 
 
        | A triangle with two equal sides  The angles opposite the equal sides are also equal |  | 
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        | The middle number (in a sorted list of numbers). Half the numbers in the list are less, and half the numbers are greater. |  | 
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        | The height of an object or place above sea level. |  | 
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        | Is a quadrilateral with one pair of opposite sides parallel. |  | 
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        | It has two pairs of sides.  Each pair is made up of adjacent sides that are equal in length.  The angles are equal where the pairs meet.  Diagonals (dashed lines) meet at a right angle, and one of the diagonal bisects (cuts equally in half) the other. |  | 
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        | Opposite sides are parallel and equal in length, and opposite angles are equal |  | 
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        | A four-sided shape where all sides have equal length.  Also opposite sides are parallel and opposite angles are equal. |  | 
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        | A rectangle is a four-sided polygon where every angle is a right angle (90°). |  | 
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        | Term 
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        | A 4-sided polygon where all sides have equal length and every angle is a right angle (90°) |  | 
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        | The region in which objects exist.  The small ball takes up less space than the big ball. |  | 
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        | Three or more points that lie on the same straight line are called to be Collinear. |  | 
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        | Two objects are coplanar if they both lie in the same plane |  | 
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