# postulates and theorems in chapter 4

## 15 terms · chapter 4 theorems and postulates for mrs. manoogian's test

### SSS

if three sides of one triangle are congruent to three sides of another triangle, then the two triangles are congruent

### SAS

If two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle, then the two triangles are congruent

### ASA

if two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, then the two triangles are congruent

### congruency of triangles is an equivalence relation

if triangle 1 is congruent to triangle 2 and triangle 2 is congruent to triangle 3, then triangle 1 is congruent to triangle 3

### triangle sum theorem

the sum of the angle measures of a triangle is 180

### the acute angles of a right triangle are complementary

the acute angles of a right triangle are complementary

### the measure of each angle of an equiangular triangle is 60

the measure of each angle of an equiangular triangle is 60

### exterior angle theorem

the measure of an exterior angle of a triangle is equal to the sum of the measures of its remote interior angles

### third angles theorem

if two angles of one triangle are congruent to two angles of another triangle, then the third pair of angles are congruent

### AAS

if two angles and a non-included side of one triangle are congruent to the corresponding angles and nonincluded side of another triangle, then the triangles are congruent

### HL

if the hypotenuse and a leg of a right triangle are congruent to the hypotenuse and a leg of another right triangle, then the triangles are congruent

### ITT

If two sides of a triangle are congruent, then the angles opposite the sides are congruent

### equilateral triangle

if a triangle is equilateral, then it is equiangular

### CITT

if two angles of a triangle are congruent, then the sides opposite those angles are congruent

### equiangular triangle

if a triangle is equiangular, then it is equilateral