Theorems, Conjectures, & Postulates Triangle Theorems Triangle Sum Theorem- The sum of the measures of the angles in every triangle is 180? Exterior Angle Theorem- The measure of an exterior angle of a triangle is equal to the sum of the measures of the two nonadjacent interior angles. Corollary to the Triangle Sum Theorem- In a right triangle, the acute angles are complementary. Base Angles Theorem ? If two sides of a triangle are congruent, then the angles opposite them are congruent. Converse of Base Angles Theorem ? If two angles of a triangle are congruent, the sides opposite them are congruent. Corollary to the Base Angle Theorem ? If a triangle is equilateral, then it?s equiangular.

# Geometry Cheat Sheet

Theorems, Conjectures, & Postulates Triangle Theorems Triangle Sum Theorem- The sum of the measures of the angles in every triangle is 180? Exterior Angle Theorem- The measure of an exterior angle of a triangle is equal to the sum of the measures of the two nonadjacent interior angles. Corollary to the Triangle Sum Theorem- In a right triangle, the acute angles are complementary. Base Angles Theorem ? If two sides of a triangle are congruent, then the angles opposite them are congruent. Converse of Base Angles Theorem ? If two angles of a triangle are congruent, the sides opposite them are congruent. Corollary to the Base Angle Theorem ? If a triangle is equilateral, then it?s equiangular.

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