circumference
the perimeter of a circle
diameter
the length of a circle
radius
the length from one side of a circle to the center
perimiter
the distance around an object measured in linear units
area
the space within a shape that is measured in square units
paralellogram
a quadrilateral with opposite sides parallel and equal
rectangle
a quadrilateral with opposite sides parallel and equal in length and has 4 90 degrees angles
square
a quadrilateral with opposite sides parallel and equal in length and has 4 90 degrees angles and all sides equal in length
trapezoid
a quadrilateral with one pair of parallel sides