Acute Angles
(KS2, Year 6)

The Lesson

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.

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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See Also

What are degrees?