Download chapter 6 geometry vocabulary

CHAPTER 6 GEOMETRY VOCABULARY
This is an alphabetical list of new vocabulary terms you will learn in Chapter 6. Glue this in your interactive
notebook so you can use it for class, homework and to study for quizzes and test. You may make a set of index
cards that include the term on the front, definition and example on the back. Check page 306 for help in finding
pages with examples. Also there are many examples in the book glossary
TERM
DEFINITION
Acute angle
An angle with a measure greater than 0
and less than 90 .
Right angle
An angle that measures 90 .
Obtuse angle
An angle that measures greater than 90
But less than 180 .
Straight Angle
An angle that measures 180 .
Vertical angles
Opposite angles formed by the intersection
of two lines. Vertical angles are congruent.
Adjacent angles
Angles that have the same vertex, share a
common side, and do not overlap.
Complementary angles
Two angles are complementary if the sum
of their measure is 90 degrees.
Supplementary angles
Two angles are supplementary if the sum
of their measures is 180 degrees.
Perpendicular lines
Two lines that intersect to form right
angles.
Parallel lines
Lines in the same plane that never intersect
or cross. The symbol ll means parallel.
Transversal
A line that intersects two or more other
lines to form eight angles.
CLASS EXAMPLE
Alternate exterior angles
Those angles on the opposite sides of the
transversal and outside the other two lines.
Alternate interior angles
Those angles on opposite sides of the
transversal and inside the other two lines.
Corresponding angles
Angles that have the same position on two
different parallel lines cut by a transversal.
Triangle
A figure formed by three line segments that
intersect only at their endpoints.
Acute triangle
A triangle having three acute angles.
Obtuse triangle
A triangle having one obtuse angle.
Right triangle
A triangle having one right angle.
Scalene triangle
A triangle with no congruent sides.
Isosceles triangle
A triangle that has at least two congruent
sides.
Equilateral triangle
A triangle that has three congruent sides.
Quadrilateral
A polygon that has four sides and four
angles.
Trapezoid
A quadrilateral with exactly one pair of
parallel opposite sides.
Parallelogram
A quadrilateral with both pairs of opposite
side parallel and congruent.
Rectangle
A parallelogram with four right angles.
Rhombus
A parallelogram with four congruent sides.
Square
A parallelogram with four congruent sides
and four right angles.
Congruent polygons
Polygons that have the same size and
measure.
Line symmetry
Figures that match exactly when folded in
half have line symmetry.
Line of symmetry
A line that divides a figure into two halves
that are reflections of each other.
Rotational Symmetry
A figure has rotational symmetry if it can
be turned less than 360 about its center and
still look like the original.
Angle of Rotation
The degree measure of the angle through
which a figure is rotated.
Reflection
A type of transformation in which a mirror
image is produced by flipping a figure over
a line.
Line of reflection
The line a figure is flipped over in a
reflection.
Transformation
A mapping of a geometric figure.
Translation
A transformation in which a figure is slid
horizontally, vertically or both.
Rotation
A transformation involving the turning or
spinning of a figure around a fixed point.
Center of rotation
The fixed point a rotation of a figure turns
or spins around.