# anglesandtriangles

## Introducing angles and triangles

geometryanglestriangles

# anglesandtriangles

Created 3 years ago

Duration 0:05:06
106
Introducing angles and triangles
Slide Content

2. ### Slide 2 - Angles

• A shape formed by two rays sharing a common endpoint; contains two rays and a vertex
• ray
• ray
• vertex
• ray—has one endpoint and goes infinitely in one direction
• vertex—point common to two rays of a triangle or two sides of a polygon
3. ### Slide 3 - Types of Angles

• Acute angle: An angle whose measure is greater than zero degrees and less than 90 degrees
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4. ### Slide 4 - Types of Angles

• Right angle: Angle that measures 90 degrees
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5. ### Slide 5 - Types of Angles

• Obtuse angle: One angle measures greater than 90 degrees and less than 180 degrees
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6. ### Slide 6 - Straight Angle

• Straight angle: A line that goes infinitely in both directions and measures 180 degrees
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• This is a ray. It only goes in one direction.
7. ### Slide 7 - Types of Triangles

• Equilateral triangle: A triangle with three congruent (equal) sides and three equal angles
• These marks indicate equality.
8. ### Slide 8 - Types of Triangles

• Isosceles triangle: A triangle with at least two congruent (equal) sides
9. ### Slide 9 - Types of Triangles

• Right triangle: Has only one right angle (90 degrees)
• This box indicates a right angle or a 90-degree angle.
10. ### Slide 10 - Types of Triangles

• Scalene triangle: A triangle that has no congruent (equal) sides
11. ### Slide 11 - Interior Angles

• Interior angles: An interior angle (or internal angle) is an angle formed by two sides of a simple polygon that share an endpoint
• Interior angles of a triangle always equal 180 degrees.
12. ### Slide 12 - Measuring Angles

• You measure angles with a protractor.
• This point goes at the vertex of the angle
• This point is 0
• This point is 0.
• Notice there are two scales. Be careful which 0 you start at.
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