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Intro to Angles
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 We'll learn what angles are!
 How to identify and measure different types of angles.
 And we’ll discover that this knowledge can help us skateboard, dance, and even enjoy birthday cake!

Discussion Questions
 Before VideoWhat attribute do you measure when you use a ruler as the measurement tool?ANSWER
I am measuring length. Length on a ruler is measured in inches or centimeters.
I am measuring duration, or the amount of time between things.
I am measuring weight.
I know that inches, feet, and meters are used to measure length. Grams, kilograms, and pounds are used for weight. Seconds, minutes, and hours are used for time. Cups, liters, and liquid ounces are used to measure capacity.
I heard the word angle when I was playing baseball. Coach told me to throw the ball at a higher angle.
 After VideoWhat is a degree?ANSWER
A degree is a unit of measure for angles. It is equal to [ggfrac]1/360[/ggfrac]th of a circle.
An acute angle is less than 90°, an obtuse angle is between 90° and 180°, and a right angle is equal to 90°.
A rectangle has all 90° angles, which means it has all right angles.
First, I need to make sure that the vertex of the angle is under the hole in the protractor. Next, I need to line one of the straight lines up with the 0° line on the protractor. Then I need to trace along the protractor from 0° until I reach the second ray. The set of numbers that I have counted up from 0° tell me the measure of an angle.
No, an angle's orientation does not affect its size.

Vocabulary
 Angle DEFINE
The rotational space between two rays connected at a common point.
 Degree DEFINE
A unit of measurement for angles. A full circle measures 360°, so 1° is [ggfrac]1/360[/ggfrac] of a circle.
 Right angle DEFINE
An angle that measures 90°, or onequarter turn on a circle.
 Acute angle DEFINE
An angle that measures less than 90°.
 Obtuse angle DEFINE
An angle that measures more than 90° and less than 180°.
 Protractor DEFINE
A measurement tool used to measure the angle between two lines (rays).
 Vertex DEFINE
The point where two lines (rays) meet and form an angle.
 Angle DEFINE

Reading Material

Practice Word Problems

Practice Number Problems

Lesson Plan

Teacher Guide