triangle
A polygon with three sides.
square
A quadrilateral with four congruent sides and four right angles.
perimeter
Sum of the lengths of all the sides.
kite
A quadrilateral that has two pairs of adjacent sides that are the same length.
diagonal
A line segment connecting any two nonadjacent vertices of a polygon.
convex
Every line segment connecting interior points that is entirely contained with the figure's interior.
parallelogram
A quadrilateral that has two pairs of opposite sides that are parallel.
rectangle
A quadrilateral with four right angles.
trapezoid
A quadrilateral that has only one pair of opposite sides that are parallel.
equilateral triangle
A triangle with three congruent sides.
polygon
A closed plane figure for which all sides are line segments.
scalene triangle
A triangle with all three sides of different lengths.
concave
A shape or solid which has a "cave" in it.
congruent
Shapes that has the same size.
isosceles triangle
A triangle with two congruent sides.
regular polygon
A polygon whose sides and angles are congruent.
n-gon
A polygon with n sides.
dodecagon
A polygon with 12 sides.
decagon
A polygon with 10 sides.
consecutive sides
Two sides that are adjacent and one after the other.
quadrilateral
A four-sided polygon.
rhombus
A parallelogram with 4 congruent sides.
hexagon
A polygon with 6 sides.
pentagon
A polygon with 5 sides.
octagon
A polygon with 8 sides.
consecutive angles
Two angles that are adjacent and one after the other.
septagon
A polygon with 7 sides.
nonagon
A polygon with 9 sides.