An acute angle is an angle
of less than 90°.
The Oxford English Dictionary defines an acute angle as "a plane angle: less than 90 degrees."
Interactive Game on the Types of Angles
Here is an interactive game to help you learn about the types of angles.
- Click on an angle so it drops into the correct "bucket."
- In total, there are 10 angle to clear.
- If an angle drops into the wrong "bucket," you will lose one of your three lives.
- Good luck!
Real Examples of Acute Angles
The angles below are all acute angles:
More about Acute Angles
What's in a Name?
Acute comes from the Latin word "acutus" meaning "sharp". An acute angle makes a sharp point.
Euclid and Acute Angles
defines angles in his book, Elements
"An acute angle is an angle less than a right angle".
Acute triangles are triangles
that have all acute angles.
Drag and Drop Game
Here is a drag-and-drop game
to help you learn about the types of angles.