Download Corollary to the Base Angles Theorem

quiz
Tell whether the pair of triangles is congruent or not and why.
1.
2.
You can not prove Triangle congruent with Side-SideAngle (SSA) and Angle-Angle-Angle (AAA)
*Use Isosceles and Equilateral
Triangles
Section 4.7
Triangles

Isosceles – a triangle with at least two
congruent sides.
Vertex angle
leg
leg
Base angle
Base angle
Base


Equilateral – a triangle with 3 congruent sides
Equiangular - a triangle with 3 congruent
angles
Base Angles Theorem
If two sides of a triangle are congruent, then the angles opposite them are
congruent.
if
AB  AC
then
B  C
Converse of Base Angles Theorem
If two angles of a triangle are congruent, then the sides opposite them
are congruent.
if
B  C
then
AB  AC
Corollaries (a statement that can be proved easily using the theorem)
Corollary to the Base Angles Theorem:
If a triangle is equilateral, then it is equiangular.
Corollary to the Converse of Base Angles Theorem:
If a triangle is equiangular, then it is equilateral.
Example1:

Find x and y.
Homework
4.7 pg. 267-268 #7-17, 23-25