1 / 9

4.7 Use Isosceles and Equilateral Triangles

4.7 Use Isosceles and Equilateral Triangles. Define Isosceles . A triangle is isosceles iff it has two or more congruent sides (yes an equilateral triangle is also isosceles). Isosceles Triangle. vertex. Leg. Leg. base angle. base angle. Base. A. C. B.

denver
Download Presentation

4.7 Use Isosceles and Equilateral Triangles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 4.7 Use Isosceles and Equilateral Triangles

  2. Define Isosceles • A triangle is isosceles iff it has two or more congruent sides (yes an equilateral triangle is also isosceles)

  3. Isosceles Triangle vertex Leg Leg base angle base angle Base

  4. A C B Isosceles Triangle Theorem (Base Angles Theorem) • If two sides of a triangle are congruent (isosceles triangle), then the angles opposite them are congruent

  5. K J M L 2. Draw JM 3. MK = ML ~ 4. JK = JL ~ 5. JM = JM ~ 6. JMK = JML ~ 7. < K = <L ~ Given: JK = JL Prove <K = <L ~ R S 1. Definition of a midpoint 1. Define M as the midpoint of the base 2. Two points determines a line ~ 3. Definition of a midpoint 4. Given 5. Reflexive Property 6. SSS 7. CPCTC

  6. Use the Isosceles Triangle Theorem

  7. A C B Converse of the Isosceles Triangle Theorem (Converse of the Base Angles Theorem) • If two angles of a triangle are congruent, then the sides opposite them are congruent

  8. Corollaries • If a triangle is equilateral, then it is equiangular • If a triangle is equiangular, then it is equilateral • If a triangle is equilateral (and equiangular) then it is a regular triangle • If a triangle is equilateral (and equiangular) then the angles are 60°

  9. Homework • Page 267/1, 2, 4-6, 8-10, 12-14, 19, 26-29, 35, 36, 52, 54, 56

More Related