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## Class 5

### Course: Class 5>Unit 9

Lesson 3: Angle types

# Recognizing angles

Sal identifies acute, obtuse, and right angles in diagrams and pictures. Created by Sal Khan.

## Want to join the conversation?

• What are real world uses for being able to identify angles of objects?
• anything that's up and right perfectly is a right angle... if you crack an door open a little its a acute angle if you open a cabinet almost al the way its obtuse
• So obtuse angles will always be bigger than right angles?
• A right angle is exactly 90 degrees. An obtuse angle, on the other hand, measures more than 90 degrees but less than 180 degrees. So, an obtuse angle is always bigger.
• This teaches us about important stuff we need to know about angles at 90 or higher. 🌱🌿 But one thing: How can you tell a obtuse angle from a acute angle?
(1 vote)
• An obtuse would be greater than 90 degrees but less than 180 degrees.
And an acute angle is less than 90 degrees and more than 0 degrees, I remember acute by small angles are "aCUTE"
• Um... are you going to finish dat cwosson?
• I wish he was my math teacher.
• how do i use a protractor
• You put the hole near the bottom of the protractor at the angle's vertex, (where the two rays meet) then measure.
(1 vote)
• I really appreciate the creative imagery xD Thanks Sal!