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math vocab words for classes with quiz or tests(Mrs. Smothers)


a location in space that has no size


series of points that extends in opposite directions without end


flat serface with many lines and extends without end in many directions


part of a line with 2 end points


part of line with one end point

Parallel Lines

lines in the same plane that never intersect

Skew Lines

lines that lie in different planes they are neither parallel or intersecting

Adjacent Angles

two angles that share a common vertex and side, but have no common interior points

Vertical Angles

A pair of opposite congruent angles formed by intersecting lines

Congruent Angles

Angles that have the same measure

Supplementary Angles

Two angles whose sum is 180 degrees

Complementary Angles

Two angles whose sum is 90 degrees


a line that intersects two or more lines in a plane at different points

Corresponding Angles

lie on the same side of the transversal and in corresponding positions

Alternate interior Angles

angles between 2 lines and on opposite sides of a transversal


a closed plane figure formed by three or more line segments

Regular polygon

a polygon with all sides and all angles Congruent

Congruent Figures

Two figures that have the same shape and size the coresponding sides and angles are congruent


set of all points in a plane that are the same distance from a given point

Central Angle

an angle whose vertex is the center of the circle

Perpendicular lines

two lines that intersect to form right angles

Segment Bisector

a segment, ray, line, or plane that intersects a segment at its midpoint

Angle Bisector

a ray that divides an angle into two congruent angles


a transformation that moves points the same distance and in the same direction


The figure after transformation

Reflectional symmetry

when one half is a mirror image of the other half

Line of symmetry

Divides a figure with reflectional symmetry into two congruent halves


Transformation that flips a figure over

Line of reflection

reflected figure or image is congruent to original figure


Transformation that turns a figure around a fixed point called Center of Rotation.

Center of Rotation

Fixed point

Rotational symmetry

You can rotate it 180 degrees or less

Acute triangle

3 acute angles

Right triangle

1 right angle

Obtuse triangle

1 obtuse angle

Equilateral triangle

3 congruent sides

Isosceles triangle

2 congruent sides

Scalene triangle

No congruent sides


4 sides


4 90 degree angles and 4 congruent sides


4 90 degree angles


4 congruent sides


The distance around a circle


A chord that passes through the center of a circle

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