7-6
DESCRIPTION
7-6. Triangles. Course 2. Warm Up. Problem of the Day. Lesson Presentation. 7-6. Triangles. Course 2. Warm Up 1. What is the name of a six-sided figure? 2. What is the definition of an acute angle? - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/1.jpg)
7-6 Triangles
Course 2
Warm UpWarm Up
Problem of the DayProblem of the Day
Lesson PresentationLesson Presentation
![Page 2: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/2.jpg)
Warm Up1. What is the name of a six-sided figure?
2. What is the definition of an acute angle?
3. The measure of one angle of two supplementary angles is 32°. What is the measure of the other angle?
hexagon
an angle that measures less than 90°
148°
Course 2
7-6 Triangles
![Page 3: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/3.jpg)
Problem of the Day
Use 6 congruent line segments to form 4 equilateral triangles. (Hint: Use toothpicks or other objects to model the segments.) Place the segments so they form a pyramid.
Course 2
7-6 Triangles
![Page 4: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/4.jpg)
Learn to classify triangles by their side lengths and angle measures.
Course 2
7-6 Triangles
![Page 5: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/5.jpg)
Vocabulary
scalene triangleisosceles triangleequilateral triangleacute triangleobtuse triangleright triangle
Insert Lesson Title Here
Course 2
7-6 Triangles
![Page 6: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/6.jpg)
Course 2
7-6 Triangles
One way to classify triangles is by the lengths of their sides.
Triangles classified by sides
A scalene trianglehas no congruent sides.
![Page 7: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/7.jpg)
Course 2
7-6 Triangles
One way to classify triangles is by the lengths of their sides.
Triangles classified by sides
An isosceles trianglehas at least 2 congruent sides
![Page 8: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/8.jpg)
Course 2
7-6 Triangles
One way to classify triangles is by the lengths of their sides.
Triangles classified by sides
In an equilateral triangle, all of the sides are congruent.
![Page 9: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/9.jpg)
Course 2
7-6 Triangles
One way to classify triangles is by the lengths of their sides. Another way is by the measures of their angles.
Triangles classified by angles
In an acute triangle, all of the angles are acute.
![Page 10: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/10.jpg)
Course 2
7-6 Triangles
One way to classify triangles is by the lengths of their sides. Another way is by the measures of their angles.
Triangles classified by angles
An obtuse triangle hasone obtuse angle.
![Page 11: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/11.jpg)
Course 2
7-6 Triangles
One way to classify triangles is by the lengths of their sides. Another way is by the measures of their angles.
Triangles classified by angles
A right triangle has one right angle.
![Page 12: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/12.jpg)
Course 2
7-6 Triangles
When classifying a triangle according to its sides and angles, use the word that describes the sides first, and use the word that describes its angles second.
Writing Math
![Page 13: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/13.jpg)
Classify each triangle according to its sides and angles.
Additional Example 1A & 1B: Classifying Triangles
Course 2
7-6 Triangles
A. Two congruent sidesacute Three acute angles
This is an isosceles acute triangle.
5 ft
9 ft9 ft
B. No congruent sidesright One right angle
This is a scalene right triangle.
24 m 25 m
7 m
isosceles
scalene
![Page 14: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/14.jpg)
Classify each triangle according to its sides and angles.
Additional Example 1C & 1D: Classifying Triangles
Course 2
7-6 Triangles
C. No congruent sides
acute Three acute angles
This is a scalene acute triangle.
D. Three congruent sides
acute Three acute angles
This is an equilateral acute triangle.
scalene
equilateral
![Page 15: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/15.jpg)
Try This: Example 1A & 1B
Insert Lesson Title Here
Course 2
7-6 Triangles
Classify each triangle according to its sides and angles.
A. Two congruent sidesobtuse One obtuse angle
This is an isosceles obtuse triangle.
B. Two congruent sides
right One right angle
This is an isosceles right triangle.
5 ft
3 ft 3 ftisosceles
isosceles
![Page 16: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/16.jpg)
Try This: Example 1C & 1D
Insert Lesson Title Here
Course 2
7-6 Triangles
Classify each triangle according to its sides and angles.
C. No congruent sidesobtuse One angle exceeding 90°
This is a scalene obtuse triangle.
D. No congruent sides
obtuse One angle exceeding 90°
This is a scalene obtuse triangle.
scalene
scalene
![Page 17: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/17.jpg)
Identify the different types of triangles in the figure, and determine how many of each there are.
Additional Example 2: Identifying Triangles
Course 2
7-6 Triangles
Type How many Name
Scalene 2 ABD, BCD
Isosceles
Right
Obtuse
Acute
ACE, ABC
ABD, BCD
ACE
ABC
2
2
1
1
![Page 18: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/18.jpg)
Try This: Example 2
Insert Lesson Title Here
Course 2
7-6 Triangles
A
BC
D
EF
G
H
I J
Identify the different types of triangles in the figure, and determine how many of each there are.
Isosceles
Obtuse
Acute
5
2
4
NameHow manyType
DJA, JDG
HJI, BCD
DFE
DJA, ADG
JDG, JHI,
BCD, DEF
![Page 19: 7-6](https://reader036.vdocuments.site/reader036/viewer/2022070400/5681351f550346895d9c8191/html5/thumbnails/19.jpg)
Lesson Quiz
Classify each triangle according to its side or angle measures.
1. 7ft, 8ft, 12ft
2. 45°, 90°, 45°
3. 12, 9, 12
4. 120°, 20°, 40°
5. Identify the different types of triangles in the figure and determine how many of each there are.
right
scalene
Insert Lesson Title Here
isosceles
obtuse
Course 2
7-6 Triangles
1 isosceles acute triangle, 1 equilateral triangle, 1 scalene right triangle