Quadrilaterals
all sides equal; all angles 90 degrees
square
all sides equal
equilateral
3 sided closed figure
triangle
less than 90 degrees
acute
represented by a dot
point
opposites sides equal, all angels 90 degrees
1 right angle
right triangle
5 sided closed figure
pentagon
exactly 90 degrees
right
has a beginning point and an end point
line segment
all sides equal; 2 pairs of parallel lines; opposite angles equal (diamond)
rhombus
all acute angles
6 sided closed figure
hexagon
more than 90 degrees but less than 180
obtuse
has a beginning point with no end point
ray
opposite sides equal, 2 pairs of parallel lines
parallelogram
1 obtuse angle
obtuse triangle
8 sided closed figure
octagon
equals 180 degrees
straight angle
goes on forever and ever in both directions
line
1 pair of parallel sides
trapezoid
2 sides equal
isosceles triangle
10 sided closed figure
decagon
tool we use to measure angles
protractor
two lines that never cross or intersect
parallel