Download presentation

Presentation is loading. Please wait.

1
Geometry Notes Section 4-1

2
What you’ll learn How to identify and name the parts of a triangle. How to identify and classify triangles by angles. How to identify and classify triangles by sides.

3
**Vocabulary Sides of a triangle Vertices of a triangle Acute triangle**

Obtuse triangle Right triangle Equiangular triangle Scalene triangle Isosceles triangle Equilateral triangle

4
**The vertices of this triangle are:**

The parts of a triangle The vertices of a triangle are the corner points joining the sides of the triangle Points are named with capital printed letters One corner is called a VERTEX more than one, VERTICES F S H The vertices of this triangle are: F, S, and H

5
**The sides of this triangle are:**

The parts of a triangle The sides are line segments Segments are named by endpoints Sides will have measure (like inches) The sides of this triangle are: F S H FS, SH, and HF

6
**The angles of this triangle are:**

The parts of a triangle Every triangle will have three angles Angles are named by “” with three points (vertex in middle) , “” with just the vertex, or “” with a number The angles of this triangle are: F S H F or SFH, S or FSH, and H or SHF

7
**You must include the Δ symbol**

NAMING A TRIANGLE Triangles are named by their vertices C THIS TRIANGLE CAN BE CALLED ΔACT ΔTAC A T ΔCAT You must include the Δ symbol

8
**Classifying Triangles by Angles**

Acute Triangles—triangles with all 3 angles measuring less than 90° Obtuse triangles—triangles with exactly ONE angle measuring between 90° and 180° Right Triangles– triangles with exactly ONE right angle (marked with a box) Equiangular Triangles—triangle with all angles exactly the same measure (all are congruent to each other)

9
**Classifying Triangles by Sides**

Scalene Triangles—triangles with no 3 sides of equal measure (no congruent sides) Isosceles triangles—triangles with at least TWO sides of equal measure (2 congruent sides) Equilateral Triangles—triangle with all sides exactly the same measure (all 3 sides congruent to each other)

10
**Parts of an Isosceles Triangle**

Vertex angle Vertex angle Vertex angle The vertex angle is always the angle between the two congruent sides; the other angles are called base angles.

11
**Example Problem #1: Find x if ΔJMN is isosceles with JM = MN. M 2x – 5**

12
Example Problem #2: ΔFGH is equilateral. With FG = x + 5, GH = 3x – 9, and FH = 2x Find x and the length of each side G x + 5 3x – 9 F H 2x - 2

13
**Example Problem #3: Classify ΔRST by its sides. R(0, 2) S(2, 5)**

14
Have you learned How to identify and name the parts of a triangle? How to identify and classify triangles by angles? How to identify and classify triangles by sides? Assignment: NON-PROOF:Worksheet 4-1 PROOF: P. 181(22-44E, 50-56E)

Similar presentations

OK

Lesson 8.3 Concept: How to classify triangles by their sides and angles. An equilateral triangle has three sides of the same length. An isosceles triangle.

Lesson 8.3 Concept: How to classify triangles by their sides and angles. An equilateral triangle has three sides of the same length. An isosceles triangle.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on bbc news channel Ppt on history of australia day Download ppt on sources of water Ppt online downloader youtube Ppt on causes of 1857 revolt leaders Download ppt on user interface Ppt on different types of chemical reactions for class 10 Download ppt on poem song of the rain Ppt on farm management Ppt on you can win book