acute triangle

A triangle with three angles that each measure between 0º and 90º.

congruentHaving the same size and shape.
corresponding anglesAngles of separate figures that are in the same position within each figure.
corresponding sidesSides of separate figures that are opposite corresponding angles.
equilateral triangleA triangle with 3 equal sides.
isosceles triangleA triangle with 2 equal sides.
obtuse triangle

A triangle with one angle that measures between 90º and 180º.

polygonA closed plane figure with three or more straight sides.
right triangleA triangle containing a right angle.
scalene triangleA triangle in which all three sides are a different length.
similarHaving the same shape but not necessarily the same size.
triangleA polygon with three sides.