Pre-Algebra Chapter 10 Vocabulary

Front 1

adjacent angle

Back 1

Two angles that have the same vertex, share a common side, and do not overlap.

Front 2

alternate exterior angles

Back 2

Nonadjacent exterior angles found on opposite sides of the transversal.

Front 3

alternate interior angles

Back 3

Nonadjacent interior angles found on opposite sides of the transversal.

Front 4

altitude

Back 4

A line segment that is perpendicular to the base of a figure with endpoints on the base and the side opposite the base.

Front 5

base

Back 5

The base of a parallelogram or a triangle is any side of the figure. The bases of a trapezoid are the parallel sides.

Front 6

bilateral symmetry

Back 6

A figure that has line symmetry has bilateral symmetry.

Front 7

center

Back 7

The given point from which all points on the circle are the same distance.

Front 8

circle

Back 8

The set of all points in a plane that are the same distance from a given point called the center.

Front 9

circumference

Back 9

The distance around a circle.

Front 10

complementary

Back 10

Two angles are complementary if the sum of their measures is 90°.

Front 11

congruent

Back 11

Line segments that have the same length, or angles that have the same measure, or figures that have the same size and shape.

Front 12

corresponding angles

Back 12

Angles that have the same position on two different parallel lines cut by a transversal.

Front 13

corresponding parts

Back 13

Parts of congruent or similar figures that match.

Front 14

diagonal

Back 14

A line segment that joins two nonconsecutive vertices of a polygon.

Front 15

diameter

Back 15

The distance across a circle through its center.

Front 16

dilation

Back 16

A transformation that alters the size of a figure but not its shape.

Front 17

exterior angles

Back 17

Four of the angles formed by the transversal and two parallel lines.

Front 18

interior angles

Back 18

Four of the angles formed by the transversal and two parallel lines. Exterior angles lie outside the parallel lines.

Front 19

line symmetry

Back 19

A figure is said to have line symmetry when two sides match.

Front 20

line of symmetry

Back 20

Each half of a figure is a mirror image of the other half when a line of symmetry is drawn.

Front 21

parallel lines

Back 21

Two lines in the same plane that do not intersect.

Front 22

parallelogram

Back 22

A quadrilateral with opposite sides parallel and congruent.

Front 23

perpendicular lines

Back 23

Lines that intersect to form a right angle.

Front 24

π

Back 24

The ratio of a circle to the diameter of the circle. Approximations for π are 3.14 or 22/7.

Front 25

polygon

Back 25

A simple closed figure in a plane formed by three or more line segments.

Front 26

quadrilateral

Back 26

A closed figure with four sides and four vertices, including squares, rectangles, and trapezoids.

Front 27

radius

Back 27

The distance from the center to any point on the circle.

Front 28

reflection

Back 28

A transformation where a figure is flipped over a line. Also called a flip.

Front 29

regular polygon

Back 29

A polygon having all sides congruent and all angles congruent.

Front 30

rhombus

Back 30

A parallelogram with four congruent sides.

Front 31

rotation

Back 31

A transformation where a figure is turned around a fixed point. Also called a turn.

Front 32

rotational symmetry

Back 32

Any figure that can be turned or rotated less than 360° about a fixed point so that the figure looks exactly as it does in its original position has rotational or turn symmetry.

Front 33

supplementary

Back 33

Two angles are supplementary if the sum of their measures is 180°.

Front 34

tessellation

Back 34

A tessellation is a pattern of repeating figures that fit together with no overlapping or empty spaces. Tessellations can be formed using transformations.

Front 35

transformation

Back 35

A movement of a geometric figure.

Front 36

translation

Back 36

A transformation where a figure is slid from one position to another without being turned. Also called a slide.

Front 37

transversal

Back 37

A line that intersects two parallel lines to form eight angles.

Front 38

trapezoid

Back 38

A quadrilateral with exactly one pair of parallel lines.

Front 39

turn symmetry

Back 39

Any figure that can be turned or rotated less than 360° about a fixed point so that the figure looks exactly as it does in its original position has rotational or turn symmetry.

Front 40

vertical angles

Back 40

Two pairs of opposite angles formed by two intersecting lines. The angles formed are congruent.