Download Geometry Key 3rd Grade

Geometry Key
Vocabulary
Word
Point
Definition
Drawing
the name of a location of an object
and in space
Line
a straight path in a plane extending
in both directions with no endpoints
Plane
a flat surface that extends without
end in all directions
Parallel Lines
two lines that never intersect
Perpendicular
Lines
two lines that intersect to form 90
degree angles.
Perimeter
The amount of space around an
object
.
A
8
3
3
8
Acute angle
an angle that measures less than 90
Right angle
an angle that measures 90
Obtuse angle
an angle that measures more than
90 but less than 180
P=22
Straight Angle
an angle that measures 180
Regular polygon a polygon with all sides of equal
length and all angles equal (i.e.
square)
Quadrilateral
a polygon with four sides
Parallelogram
a quadrilateral with two pairs of
parallel sides
Square
a polygon with four equal sides and
four right angles
Rectangle
a polygon with four sides and four
right angles
Rhombus
a polygon whose four sides are
congruent and whose opposite
angles are congruent
Trapezoid
a quadrilateral having two parallel
and two non-parallel sides
Congruent
Figures that are the same shape and
size
Pentagon
a five-sided polygon
Hexagon
a six-sided polygon
Octagon
an eight-sided polygon
Triangulating
the process of dividing a polygon
into non-overlapping triangles
Circle
a closed plane curve consisting of
all points at a given distance from a
point within it called the center
Equilateral
Triangle
a triangle that has all three sides
equal
Right Triangle
a triangle that has one angle
measuring 90 degrees.
Scalene
Triangle
a triangle that has no equal sides
Isosceles
Triangle
a triangle that has 2 sides equal
Line of
symmetry
a line that separates a figure or
object into identical parts
Notes:
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