Download presentation

Presentation is loading. Please wait.

Published byTiffany Trippett Modified over 3 years ago

1
4.6 Isosceles Triangles What you’ll learn: 1.To use properties of isosceles triangles 2.To use properties of equilateral triangles.

2
Parts of an isosceles Triangle Legs – the 2 congruent sides Base – the other side (it is not always sitting on the base) Vertex angle – angle formed by the 2 legs of the triangle. Base angle – angle formed by a leg and the base. leg Base Base angles Vertex Angle

3
Theorems Theorem 4.9 – Isosceles Triangle Theorem If 2 sides of a triangle are congruent, then the angles opposite those sides are congruent. If AB BC, then A C. Theorem 4.10 If 2 angles of a triangle are congruent, then the sides opposite those angles are congruent. If A C, then AB BC. A B CA B C

4
Corollaries Corollary 4.3 A triangle is equilateral iff it is equiangular. Corollary 4.4 Each angle of an equilateral triangle measures 60 .

5
Given: AB=CB=BD, ACB BCD Prove: A D 1.AB=CB=BD, ACB BCD 2. A ACB D BCD 3. A D 1.Given 2.Isosceles triangle theorem 3.Substitution C D B A

6
Examples Use the figure. a.Name 2 congruent angles MLN N b.Name 2 congruent segments. PM PL Use the figure to find x a. 2x+6x+6+6x+6=180 14x+12=180 x=12 b. x+x+3x=180 x=36 P L M N (6x+6) 2x xx 3x

7
Homework p. 219 10-30 even 35-37 all

Similar presentations

OK

Triangles and Angles Sec 4.1 GOALS: To classify triangles by their angles and sides To find missing angle measures in triangles.

Triangles and Angles Sec 4.1 GOALS: To classify triangles by their angles and sides To find missing angle measures in triangles.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on google driverless cars View my ppt online shopping Download ppt on turbo generator construction Ppt on ideal gas law definition Ppt on the road not taken essay Ppt on atrial septal defect definition Ppt on effective leadership skills Ppt on cell organelles and their functions Ppt on soft skills for bpo Ppt on ancient olympic games