Classifying Triangles | How to Name Triangles (by Sides and Angles)
From Math with Mr. J
5 min4thMath
Summary
How to name, measure, and draw angles with a protractor -- acute, right, obtuse, and straight. Mr. J reads the protractor carefully.
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Teaching resources
Discussion questions
An angle is the turn between two rays; a protractor measures it in degrees.
- What is the difference between an acute and an obtuse angle?
- How many degrees is a right angle? A straight angle?
- How do you line up a protractor to measure?
Quick work-a-long
Words to know: angle, degree, acute, obtuse, right angle
- Measure an angle in the room with a protractor.
- Draw a 45-degree angle and a 120-degree angle.