# Types of Triangles

Acute Triangle Acute Triangle. more ... A triangle that has all angles less than 90° (90° is a Right Angle) See: Obtuse Triangle. Triangles - Equilateral, Isosceles and Scalene.

Equilateral Triangle In geometry, an equilateral triangle is a triangle in which all three sides are equal. In the familiar Euclidean geometry, equilateral triangles are also equiangular; that is, all three internal angles are also congruent to each other and are each 60°.

Isosceles Triangle Isosceles Triangle . Two equal sides Two equal angles Scalene Triangle . No equal sides No equal angles . What Type of Angle? Triangles can also have names that tell you what type of angle is inside: Acute Triangle . All angles are less than 90° ...

image: ck12.org
Obtuse Triangle Obtuse Triangle. more ... A triangle that has an angle greater than 90° See: Acute Triangle. Triangles - Equilateral, Isosceles and Scalene.

Scalene Triangle Equilateral, Isosceles and Scalene. There are three special names given to triangles that tell how many sides (or angles) are equal. There can be 3, 2 or no equal sides/angles: