quadrilateral
A polygon with 4 sides.
triangle
A polygon with 3 sides.
acute angle
An angle less than 90 degrees.
obtuse angle
An angle with greater than 90 degrees.
perpendicular
Intersecting at right angles.
polygon
A closed figure made with three or more line segments.
ray
A half-line extending from a point.
right angle
An angle that is exactly 90 degrees.
square
A quadrilateral with 4 equal sides and 4 90 degree angles.
isosceles triangle
A triangle with at least 2 equal sides.
scalene triangle
A triangle with 3 unequal sides.
parallel lines
Lines that do not intersect.
parallelogram
A quadrilateral with opposite parallel lines.
rhombus
A parallelogram that opposite congruent angles and sides. Ex: a square that appears to lean.
trapezoid
A quadrilateral with only two parellel sides.
obtuse triangle
a triangle with one obtuse angle
equilateral triangle
a triangle with three equal sides
intersecting lines
Lines that cross at exactly one point
line
a straight path that extends infinitely in one direction
rectangle
a parallelogram with four right angles
angle
two rays or line segments with a common endpoint