Isosceles, Equilateral, and Right Triangles Chapter 4.6
Isosceles Triangle Theorem Isosceles The 2 Base s are Base angles are the angles opposite the equal sides.
Isosceles Triangle Theorem B If AB BC, then A C
Isosceles Triangle Theorem B If A C then AB BC
Sample Problem Solve for the variables mA = 32° mB = (4y)° mC = (6x +2)° A C B 32 + 32 + 4y = 180 4y + 64 = 180 4y = 116 y = 29 6x + 2 = 32 6x = 30 x = 5
Find the Measure of a Missing Angle 180o – 120o = 60o 180o – 30o = 150o Lesson 6 Ex2
A. 25 B. 35 C. 50 D. 130 A B C D Lesson 6 CYP2
A. Which statement correctly names two congruent angles? B. C. D. A B C D Lesson 6 CYP3
B. Which statement correctly names two congruent segments? D. A B C D Lesson 6 CYP3
Equilateral Triangle Theorem Equilateral Equiangular Each angle = 60o !!!
Use Properties of Equilateral Triangles Linear pair Thm. Substitution Subtraction Answer: 105 Lesson 6 Ex4
A. x = 15 B. x = 30 C. x = 60 D. x = 90 A B C D Lesson 6 CYP4
A. 30 B. 60 C. 90 D. 120 A B C D Lesson 6 CYP4
Don’t be an ASS!!! Angle Side Side does not work!!! (Neither does ASS backward!) It can not distinguish between the two different triangles shown below. However, if the angle is a right angle, then they are no longer called sides. They are called…
Hypotenuse-Leg Theorem If the hypotenuse and one leg of a right triangle are congruent to the corresponding parts in another right triangle, then the triangles are congruent.
ABC XYZ Why? HL Theorem
Prove XMZ YMZ Given Given Reflexive ZMX ZMY HL Thm Step Reason X Y Z M Given Given mZMX = mZMY = 90o Def of lines Reflexive ZMX ZMY HL Thm
Corresponding Parts of Congruent Triangles are Congruent Given ΔABC ΔXYZ You can state that: A X B Y C Z AB XY BC YZ CA ZX
Suppose you know that ABD CDB by SAS Thm Suppose you know that ABD CDB by SAS Thm. Which additional pairs of sides and angles can be found congruent using Corr. Parts of s are ?
Complete the following two-column proof. Statements Reasons 1. 1. Given 2. 2. Isosceles Δ Theorem 3. 3. Given 4. 4. Def. of midpoint Lesson 6 CYP1
SAS Thm. Corr. Parts of s are Complete the following two-column proof. Proof: 4. Reasons Statements 4. Def. of midpoint 5. ______ 6. 6. ? 5. ΔABC ΔADC ? A B C D SAS Thm. Corr. Parts of s are Lesson 6 CYP1
Homework Video C Ch 4-6 pg 248 1 – 10, 14 – 27, 32, 33, 37 – 39, & 48 Reminder! Midpoint Formula: