Glossary For Tennessee Geometry, Semester A v2.0

This flashcard set covers the key geometric terms, definitions, and transformations from the Tennessee Geometry Semester A v2.0 glossary.

angle

a figure formed by two rays that have a common endpoint called the vertex; often measured in degrees

angle bisector

a line, ray, or segment that divides an angle into two congruent angles

angle of symmetry

the smallest angle by which a figure can be rotated to map back on itself

bisect

to divide a line, angle, or figure into two congruent parts

circle

the set of all points in a plane that are equidistant from a given point, called the center of the circle

circumference

the perimeter or distance around a circle

congruent angles

angles with the same measure

congruent line segments

segments with the same length

Converse

a conditional statement in which the hypothesis and the conclusion are switched

Coordinate

position of an object given its $x$ and $y$ distance from an origin

Counterexample

an example used to refute, or disprove, a statement that is believed to be true

Degenerate triangle

A triangle formed by $3$ points in a line segment. This occurs when the sum of two side lengths is equal to the length of the third side.

Diameter

a segment that has both endpoints on a circle and also passes through the center of the circle

Dilation

a transformation where an object is enlarged or reduced by a given scale factor

Distance

the amount of space between two points

Image

the resulting figure after a transformation has been applied

Isosceles trapezoid

a trapezoid in which the legs are congruent

Kite

a quadrilateral with exactly one pair of congruent opposite angles and two pairs of congruent adjacent sides

line

a connected set of points that extends infinitely in two opposite directions; has infinite length, but no width or height

line segment

a part of a line that begins at one point and ends at another point; line segment consists of the endpoints $A$ and $B$ and all points between $A$ and $B$

linear pair

a pair of adjacent angles formed by two intersecting lines

median

a line segment that joins the vertex of a triangle to the midpoint of the opposite side

midpoint

the point that divides a line segment into two congruent segments

order of rotational symmetry

the number of times a figure maps onto itself in one rotation

orientation

the way a figure is positioned or facing

parallel lines

lines that are equidistant from each other at every pair of corresponding points and will never intersect

parallelogram

a quadrilateral with two sets of parallel sides

perpendicular bisector

a line, ray, or segment that is perpendicular to a segment at its midpoint

perpendicular lines

lines that intersect to form right angles

Midsegment (of a triangle)

a line segment that connects the midpoints of two sides of a triangle

Inclusive Inequality

an inequality represented by either the symbol $s$ (less than or equal to) or the symbol $2$ (greater than or equal to)

plane

a flat surface that extends infinitely in all directions; has infinite length and width, but no height

point

a position in space; shown by a dot, but having no length, width, or height

preimage

the original figure before the transformation is applied

Radius

a segment with one endpoint at the center of a circle and the other on the circle

translation

a transformation where points are moved a specified distance along a line parallel to a specified line

trapezoid

a quadrilateral with at least one pair of parallel sides

Ray

a part of a line with one fixed endpoint that extends infinitely in one direction

Reflection

a transformation where each point in a preimage and its corresponding point in the image are at equal distances from a given line, the line of reflection, and the line segment joining two corresponding points is perpendicular to the given line

Regular polygon

a polygon in which all sides are congruent and all angles are congruent

Rigid transformation

a transformation where side lengths and angles are preserved, resulting in an image that is congruent to the preimage

Rotation

a transformation where points are moved in a circular arc about a given point

Slope

the measure of a line's steepness, found by the ratio of vertical rise to horizontal run

Strict Inequality

an inequality represented by either the symbol $<$ (less than) or the symbol $>$ (greater than)

vertical angles

a pair of nonadjacent angles formed by two intersecting lines or line segments