1. AIM: Classify Triangles
Do Now
Weekly Quiz #12
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2. Polygon
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3. Anticipatory Set:
Write the definition of each type of angle and then draw each type of angle.
Acute Angle Right Angle Obtuse Angle Straight Angle
Definition
Drawing
1.) Draw an additional line segment that will change the acute,
obtuse, and right angles into triangles.
2.) Why can the straight angle not be changed into a triangle if
you drew only one additional line segment?
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4. Classifying Triangles by Angle Measures
1.) Acute Triangle: A triangle where all angles are acute.
2.) Obtuse Triangle: A triangle that has one obtuse angle.
3.) Right Triangle: A triangle that has one right angle.
Classifying Triangles by Side Lengths
4.) Scalene Triangle: A triangle that has no congruent sides.
5.) Isosceles Triangle: A triangle that has at least two
congruent sides.
6.) Equilateral Triangle: A triangle that where all of the sides
are congruent.
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5. THINK-PAIR-SHARE
Classify each triangle according to its sides and angles.
a.) b.)
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6. 1 Indentify the triangle
below.
A Equilateral Triangle
B Isosceles Acute Triangle
C Isosceles Right Triangle
D Isosceles Obtuse Triangle
E Scalene Acute Triangle
F Scalene Right Triangle
G Scalene Obtuse Triangle
1 2
4 3
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7. 2
A
B
C
D
E
F
G
1 2
4 3
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8. 3
A
B
C
D
E
F
G
1 2
4 3
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9. 4
A
B
C
D
E
F
G
1 2
4 3
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10. 5
A
B
C
D
E
F
G
1 2
4 3
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11. 6
A
B
C
D
E
F
G
1 2
4 3
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12. 7
A
B
C
D
E
F
G
1 2
4 3
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13. 8
A
B
C
D
E
F
G
1 2
4 3
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14. 9
A
B
C
D
E
F
G
1 2
4 3
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15. BEFORE YOU LEAVE: Trade-a-Triangle
1.) Create a triangle with your partner.
2.) Exchange the example with the other partnership in your
group and classify their triangle by the sides and angles.
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16. Mr. Tjersland's Math 7
Homework: None
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17. AIM: Classify Triangles
10 Indentify the triangle
below.
A Equilateral Triangle
B Isosceles Acute Triangle
C Isosceles Right Triangle
D Isosceles Obtuse Triangle
E Scalene Acute Triangle
F Scalene Right Triangle
G Scalene Obtuse Triangle
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