What is a triangle? Triangles can be classified by their angles. There are four different classifications by angles. Equiangular triangles are triangles.

Slides:

Advertisements

Similar presentations

Report by Jennifer Johnson

Advertisements

Parallel Lines and Planes Section Definitions.

Triangles. A triangle is a polygon with three sides.

DO NOW 1) X = 180 2) 55 + X = 180 3) X + 58 = 90 4) 31 + X = 90.

Chapter 3 Review.

4.1 Triangles and Angles.

Applying Triangle Sum Properties

ADVANCED GEOMETRY 3.6 Types of Triangles LEARNER OBJECTIVE: Students will classify triangles by sides and by angles and will complete problems and proofs.

Classifying Triangles Students will classify triangles using the lengths of the sides and the angles. S. Calahan October 2010.

Classify Triangles Standard 4C.

TRIANGLES (There are three sides to every story!).

A triangle can be classified by _________ and __________. sidesangles There are four ways to classify triangles by angles. They are Equiangular Acute.

2.7 – Triangles. Type of ∆DefinitionPicture Equilateral Triangle CLASSIFICATION BY SIDES All sides are ≅

Classifying Triangles Angle Measures of Triangles.

4.1 – Apply Triangle Sum Properties

Triangles 11.2.

Chapter 4.1 Notes: Apply Triangle Sum Properties Goal: You will classify triangles and find measures of their angles.

Warmup – grab a book Room , submit answers for x and y.

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

Section 3-4: Parallel Lines and the Triangle Angle-Sum Theorem.

Triangles Geometry Mr. Zampetti Unit 3, Day 1. Today’s Objectives To learn new strategies that will help find the measures of angles in a triangle To.

4-1 Classifying Triangles

Triangle Classification. Objectives Classify triangles by their angle and side measures Find the sum of the measure of the interior and exterior angles.

Goal, to classify triangles by their sides and by their angles.

4-1 Triangles and Angles. Theorem 4.1: Triangle Sum The sum of the measures of the interior angles of a triangle is 180 . xx yy zz  x +

Types of Triangles. Angles The angles in a triangle add up to o + 60 o + 60 o =

Triangles and Angles Classifying Triangles. Triangle Classification by Sides Equilateral 3 congruent sides Isosceles 2 congruent sides Scalene No congruent.

4.1 Classifying Triangles textbook page 173 Classification by Sides  Equilateral – 3 congruent sides  Isosceles – 2 congruent sides  Scalene – no.

Classifying Triangles. Two Ways to Classify Triangles  By Their Sides  By Their Angles.

Scalene triangle: A scalene triangle is a triangle that has no equal sides. The following is a scalene triangle.

Warm Ups Classify each angle Classify each angle Solve Each Equation x= x+105= x + 58 = x = 90.

Triangles The sum of the measures of the angles of a triangle is 180 degrees. m A + m B + m C = 180 o A BC An angle formed by a side and an extension.

Triangles Chapter What is the sum of the angles inside a triangle? 180º? Prove it m Given A B C Angle Addition Postulate/Definition of a Straight.

Triangles and Their Angles Geometry – Section 4.1.

3-4 Angles of a Triangle. A Triangle is a figure formed by three segments joining three noncollinear points. 1) Classifying triangles by their sides.

Classify These Triangles by Sides and Angles. Chapter 4 Congruent Triangles Section 4.1: Triangle Sum Properties Todays Objective: Determine if a right.

4.1 Triangle Angle Sum and Properties. How many degrees in a triangle? The sum of the angles in any triangle is exactly 180 degrees.

Applying Triangle Sum Properties

5-1 Classifying Triangles

Warm Up 5-1 Classify each angle as acute, obtuse, or right

3.6 Types of Triangles Objective:

Lesson 3-4 Angles of a Triangle (page 93)

Geometry 4.1 Triangle and Angles.

Section 3-4 Angles of a Triangle.

Triangles: Classifications, Angles and More

CLASSIFICATIONS, ANGLES AND MORE!!

Classifying Triangles

Chapter 4: Congruent Triangles

ZONK!!!!!!!!!!!!! Chapter

Classifying Triangles Using Pythagorean Theorem

4.1 Triangles and Angles.

Parallel Lines and Planes

Lesson 3: Parallel Lines and the Triangle Angle-Sum Theorem

Objectives -triangle names -remote interior -exterior

Triangles and Angles Section 4.1 and 4.2.

Objective - To classify triangles.

Triangles Guided Notes

Add up all the sides Perimeter of Area of a Rectangle: ANY polygon:

3-2 Properties of Parallel Lines

Bellringer 3. slope 1/3 , y-intercept  (2, 3), (1, 6)

Converse Definition The statement obtained by reversing the hypothesis and conclusion of a conditional.

3-3 Parallel Lines & the Triangle Angle Sum Theorem

4-1 Vocabulary Acute triangle Equiangular triangle Right triangle

4.1 – Apply triangle sum properties

4-1 Classifying Triangles

Presentation transcript:

What is a triangle?

Triangles can be classified by their angles. There are four different classifications by angles. Equiangular triangles are triangles with three congruent angles. Acute triangles are triangles with three acute angles. Obtuse triangles are triangles with one obtuse angle and two acute angles. Right triangles are triangles with one right angle and two acute angles.

WHITE NOTE CARD Triangle Classification by Angles Equiangular - three congruent angles AcuteObtuseRight 3 acute angles1 obtuse angle and 2 acute angles 1 right angle and 2 acute angles

Triangles can also be classified by their sides. What is an equilateral triangle? 3 congruent sides 3 acute angles 3 congruent angles

Triangles can also be classified by their sides in three different ways. What is an isosceles triangle? 2 congruent sides could be acute, right, or obtuse 2 congruent angles

There are three ways to classify triangles by sides. What is a scalene triangle? no congruent sides could be acute, right, or obtuse no congruent angles

WHITE NOTE CARD Triangle Classification by Sides EquilateralIsoscelesScalene 3 congruent sides 3 congruent angles Acute triangle 2 congruent sides 2 congruent angles Acute, right, or obtuse No congruent sides No congruent angles Acute, right or obtuse

Angle Sum Theorem What is the sum of the measures of the angles in a triangle? Prove that the sum of the angles in a triangle is 180º. º Note card

Given: ABC is a triangle. A B C (Number the angles for convenience) Prove:  1 +  2 +  3 = 180 STATEMENTS REASONS 1. ABC is a triangle 1. Given 2.Draw a line through B that is parallel to AC 2. Parallel Postulate 3.  4 +  2 +  5 =  1   4 and  3   5 5.  1 +  2 +  3 = If two parallel lines are cut by a transversal then the alternate interior angles are congruent. 5. Substitution Property Definition of Supplementary angles Click on the reason for an explanation.  4 +  2 +  5 = 180

COLORED NOTE CARD Angle Sum Theorem The sum of the measures of the angles in a triangle is 180º.

The Parallel Postulate If you are given a line and a point not on the line, there is exactly one line that can be drawn through the point that is parallel to the line. A B C

You can draw this line because it does not change the given information. A B C Return