point
a fixed location in space
line
a figure made up of points that extend forever in both directions
ray
a figure that has one endpoint and extends forever in the other direction
line segment
a piece of a line marked by two endpoints
parallel lines
a pair of lines that are the same distance apart and will never cross or intersect
perpendicular lines
a "special" pair of intersecting lines that cross at a 90 degree, right angle
intersecting lines
a pair of lines that cross or will eventually cross
endpoints
points that mark the ends of a line segment or end of a ray
vertex
point where two rays meet to create an angle
angle
two rays share an endpoint and extend forever in different directions
acute angle
an angle that measures between 0-90 degrees
right angle
an angle that measures exactly 90 degrees
obtuse angle
an angle that measures between 90 and 180 degrees
straight angle
an angle that measures exactly 180 degrees
polygon
a closed figure with three or more straight sides
triangle
a three sided polygon
equilateral triangle
a triangle that has three equal length sides
isosceles triangle
a triangle that has AT LEAST two equal length sides
scalene triangle
a triangle that has no equal length sides
right triangle
a triangle with one right angle
acute triangle
a triangle with 3 acute angles
obtuse triangle
a triangle with one obtuse angle
quadrilateral
a 4-sided polygon
parallelogram
a quadrilateral with two sets of parallel lines
rectangle
a quadrilateral with 2 pairs of parallel sides and 4 right angles
square
a quadrilateral with 2 pairs of parallel lines, 4 equal length sides, 4 right angles ( a "special" type of rectangle)
rhombus
a quadrilateral with 2 pairs of parallel lines, 4 equal length sides
trapezoid
a quadrilateral with one set of parallel lines