What Are Angles?

Amanda McElveen4th Grade

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What is a Ray?

• A ray is a “straight” line that begins at a certain point but extends forever in one direction.

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What is an Angle?

• Two rays that share the same endpoint form an angle.

Vertex

Ray 1

Ray 2

Angle

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What is a Right Angle?

• A right angle is two rays that meet at a right angle.

Ray 1

Ray 2Vertex

Right Angle

Example

Ray 1

Ray 2

Right Angle

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What is a Acute Angle?

• An acute angle is an angle measuring less than a right.

Vertex

Ray 1

Ray 2

Acute Angle

Example

Ray 1

Ray 2

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What is an Obtuse Angle?

• An obtuse angle is an angle that measure greater than a right angle but less than a straight line.

Right Angle

Straight Line

Obtuse angle

Example

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Quiz Time!

• You will need paper and pencil.

• For each example following write if it is a right angle, obtuse angle, or acute angle.

• Correct answers will follow the quiz.

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Example Question

What kind of angle is this?

A. Right Angle

B. Obtuse Angle

C. Acute Angle

Answer:

C. Acute Angle

Leonardo da Vinci: Vitruvian Man

Amanda McElveen 9

Question 1

What kind of angle is this?

A. Right Angle

B. Obtuse Angle

C. Acute Angle

Leonardo da Vinci: The Last Supper

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Question 2

What kind of angle is this?

A. Right Angle

B. Obtuse Angle

C. Acute Angle

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Question 3

What kind of angle is this?

A. Right Angle

B. Obtuse Angle

C. Acute Angle

Jacques-Louis David:

The Death of Marat

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Question 4

Pietro Ronzelli: Nativita di Maria

What kind of angle is this?

A. Right Angle

B. Obtuse Angle

C. Acute Angle

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Question 5

What kind of angle is this?

A. Right Angle

B. Obtuse Angle

C. Acute Angle

Pablo Picasso

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Answers

1. A. Right Angle2. C. Acute Angle3. B. Obtuse Angle4. B. Obtuse Angle5. A. Right Angle