4th Grade - Math / Geometry / Cumulative

Terms in this set (37)

parallel lines
lines in the same plane that never intersect
line
a straight path that goes on forever in opposite directions
line segment
part of a line that has two endpoints
perpendicular
lines, line segments, or rays that form right angles
point
a location in a plane usually shown by a dot
intersecting lines
lines that pass through the same point
ray
a part of a line with one endpoint and that goes forever in one direction
angle
a figure formed when two rays have the same endpoint
right angle
an angle that is a square corner OR 90 degrees
acute angle
an angle that is open less than a right angle (less than 90 degrees)
obtuse angle
an angle that is open form than a right angle (more than 90 degrees), but less than a straight line (less than 180 degrees).
degree
a unit for measuring angles.
endpoint
the point at either end of a line segment or the beginning point of a ray
protractor
a semicircular tool for measuring and constructing angles
straight angle
an angle that measures 180 degrees
degree
If the angle formed by the two rays represents 1/360 of the circle, we say the angle measures 1 degree
angle measure
when you find the degrees of an angle
180 degrees
45 degrees
polygon
a closed plane figure with straight line segments for its sides
quadrilateral
a polygon with four sides
triangle
a polygon with three sides
vertex or vertices
a point that is shared by two sides of an angle or two sides of a polygon
pentagon
a polygon with 5 sides
Hexagon
a polygon with 6 sides
octagon
a polygon with 8 sides
equilateral triangle
a triangle with 3 equal sides
isosceles triangle
a triangle with two equal sides
scalene triangle
a triangle with NO equal sides
right triangle
a triangle with ONE right angle
acute triangle
a triangle with THREE acute angles
obtuse triangle
a triangle with ONE obtuse angle
rhombus
a quadrilateral that has:
- opposite sides that are parallel
- all of its sides are the same length
trapezoid
a quadrilateral that has:
- only one pair of parallel sides
parallelogram
a quadrilateral that has:
- 2 pairs of parallel sides
rectangle
a quadrilateral that has 4 right angles
and is also a parallelogram
square
a quadrilateral that has 4 right angles and all sides are the same lengths.
It is also a parallelogram, rectangle, and rhombus
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