Matching Pairs The properties of triangles.Online version Match the types of triangles with their descriptions based on the classification according to internal angles and according to the length of its sides. by eileen tatiana saenz lugo 1 Right 2 Scalene 3 Acute 4 Isosceles 5 Oblique 6 Equilateral Two equal sides and one unequal. It has an angle of 90º (right). All its angles measure less than 90º (acute). It has an angle of more than 90º (obtuse). All sides uneven. All sides are equal.