Polygon Properties

Proving shapes to be polygons by looking at their properties and not their visual appearance is important. Make sure you know all the polygon properties and how to determine if they are what they look like!

PERPENDICULAR SIDES: For sides to be perpendicular their slopes must be opposite reciprocals
(for example: if there is a slope of -4/5 the opposite reciprocal is 5/4)
(for example: if there is a slope of 8 the opposite reciprocal is -1/8)

PARALLEL SIDES: For sides to be parallel their slopes must be the same

CONGRUENT SIDES: Congruent means they are the same length

SQUARE
Quadrilateral
Adjacent sides are perpendicular
All sides are equal length
Opposite sides are parallel

RECTANGLE
Quadrilateral
Adjacent sides are perpendicular
Opposite sides are equal length
Opposite sides are parallel

RHOMBUS
Quadrilateral
All sides are equal length
Opposite sides are parallel

PARALLELOGRAM
Quadrilateral
Opposite sides are parallel
Opposite sides are equal length

KITE
Quadrilateral
2 pairs of adjacent sides are of equal length
Diagonals are perpendicular

TRAPEZOID
Quadrilateral
1 set of opposite sides are parallel

RIGHT TRIANGLE
3 sides
2 of the sides are perpendicular

ISOSCELES TRIANGLE
3 sides
2 of the sides are of equal length

EQUILATERAL TRIANGLE
3 sides
All sides are equal length