Acute Angles
(KS2, Year 6)
An acute angle is an angle of less than 90°.

acute angle

Dictionary Definition

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 angles to clear.
  • If an angle drops into the wrong "bucket," you will lose one of your three lives.
  • Good luck!
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Real Examples of Acute Angles

The angles below are all acute angles:

examples of acute angles. 75 degrees, 30 degrees and 89 degrees

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

Euclid defines angles in his book, Elements. Definition 12: "An acute angle is an angle less than a right angle".

Acute Triangles

Acute triangles are triangles that have all acute angles.

acute triangle

Drag and Drop Game

Here is a drag-and-drop game to help you learn about the types of angles.
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This page was written by Stephen Clarke.