# Types of Triangles

Types of triangles by its interior angles (acute triangle, right triangle, obtuse triangle) and by its sides(scalene triangle, isosceles triangle, equilateral triangle).

## By Its Interior Angles

Acute Triangle:

its interior angles are all acute angles.

0 < m∠(purple) < 90

Right Triangle:

it has a right angle.

m∠(blue) = 90

Leg:

the sides that are adjacent to the right angle

Hypotenuse:

the side that is opposite to the right angle

Obtuse Triangle:

it has an obtuse angle.

90 < m∠(red) < 180

## By Its Sides

Scalene Triangle:

it has no congruent sides.

Isosceles Triangle:

it has two congruent sides (& angles).

Leg:

congruent sides

Base:

the side that is adjacent to both congruent angles

Equilateral Triangle:

it has three congruent sides (& angles).