###
area

the number of square units needed to cover a surface

###
square units (sq.units)

a unit of area with dimensions 1 unit x 1 unit

###
formula

a set of symbols that expresses a mathematical rule

###
tiling

a repeating pattern of closed figures that covers a surface with no gaps and no overlaps

###
polygon

a plane shape having 3 or more straight side

###
regular polygon

polygon with all sides and all angles equal

###
irregular polygon

a polygon with all sides and all angles not equal

###
parallelogram

a quadrilateral whose opposite sides are parallel and congruent

###
congruence

having the same size and shape

###
face

the side of a three dimensional figure

###
edge

the line made where two or more faces of a solid figure meet

###
vertex (vertices)

the point where two or more rays meet; the point of intersection of 2 sides of a polygon; the point of intersection of three or more edges of a solid figure; the top point of a cone

###
angle

a figure formed by two rays that meet at a common endpoint

###
circumference

the distance around a circle

###
diameter

a line segment passing through the center of a circle with both ends touching the circumference

###
radius

a line segment with one endpoint at the center of the circle and the other endpoint on the circle

###
pi

the relationship of the circle's circumference to its diameter, when used in calculations, pi is typically approximated as 3.14

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