Answer:
An acute triangle - interior angles are always less than 90 degrees with different side measures.
An obtuse triangle - one of the interior angles is more than 90 degrees. if one angle measures more than 90 degrees, then the sum of the remaining two angles is less than 90 degrees.
An right triangle - a triangle with a right angle (90 degrees)
Equilateral triangle has three equal sides. Isosceles triangles has two equal side lengths. Scalene triangles has no equal side lengths