Acute Triangle Definition A triangle that has three acute angles.
Right Triangle Definition A triangle with one right angle.
Obtuse Triangle Definition A triangle with one obtuse angle.
Median (in a triangle) Definition A segment that has its endpoints on a vertex of the triangle and the midpoint of the opposite side.
Angle Bisector (in a triangle) Definition A segment from a vertex to the opposite side that separates the angle into two congruent angles.
Altitude (in a triangle) Definition The perpendicular segment from a vertex of the triangle to the line containing the opposite side.
Parallelogram Definition A quadrilateral with two pairs of parallel sides.
Rectangle Definition An equiangular quadrilateral.
Rhombus Definition An equilateral quadrilateral.
Square Definition A regular quadrilateral.
Kite Definition A quadrilateral with two pairs of consecutive sides that are congruent and no opposite sides congruent.
Trapezoid Definition A quadrilateral with exactly one pair of parallel sides.