Geometry Chapter 4 Theorems And Postulates

Front 1

Third Angle Theorem (theorem 4-1)

Back 1

If two angles are congruent to two angles of another triangle, then the third angles are congruent.

Front 2

Side-Side-Side (SSS) Postulate (Postulate 4-1)

Back 2

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

Front 3

Side-Angle-Side (SAS) Postulate (Postulate 4-2)

Back 3

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

Front 4

Angle-Side-Angle (ASA) Postulate (postulate 4-3)

Back 4

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.

Front 5

Angle-Angle-Side (AAS) theorem (theorem 4-2)

Back 5

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

Front 6

Isosceles triangle theorem (theorem 4-3)

Back 6

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

Front 7

Converse of the Isosceles triangle theorem (theorem 4-4)

Back 7

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

Front 8

Theorem 4-5

If a line bisects the vertex angle of an isosceles triangle, then the line is also the what of the base?

Back 8

perpendicular bisector

If a line bisects the vertex angle of an isosceles triangle, then the line is also the perpendicular bisector of the base.

Front 9

Corollary to the Isosceles triangle Theorem (theorem 4-3)

Back 9

If a triangle is equilateral, then the triangle is equiangular

Front 10

Corollary to the converse of the isosceles triangle theorem (theorem 4-4)

Back 10

If a triangle is equiangular, then the triangle is equilateral

Front 11

Hypotenuse-Leg (HL) Theorem (Theorem 4-6)

Back 11

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