C- 12  In a triangle, the longest side is opposite the largest angle and the shortest side is opposite the smallest angle.

C- 13   If a triangle is isosceles, then the base angles are equal in measure . (Isosceles Triangle Conjecture)

C- 14   If a triangle has two angles of equal measure, then the triangle is isosceles. (Converse of the Isosceles Triangle Conjecture)

C- 15   An equilateral triangle is equiangular and, conversely, an equiangular triangle is equilateral. (Equilateral Triangle Conjecture)