Topic: Angles E2.4 – Identify and Classify Angles

Ontario Curriculum Expectation:

4.E2.4 identify angles and classify them as right, straight, acute, or obtuse.

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Acute Angle

When an angle is less than 90º, it is called an acute angle.

 

Right Angle

A quarter of a circle is 90º. It is called a right angle.

 

Obtuse Angle

When an angle is more than 90º, it is called an obtuse angle.

 

Straight Angle

When an angle is exactly 180º, it is called a straight angle.