Equilateral Triangles
(KS2, Year 6)
Note: The lines through the sides of the triangle in the image above indicate they are of equal length. The arcs indicate the angles are equal.
Dictionary Definition
The Merriam-Webster dictionary defines an equilateral triangle as "a triangle in which all three sides are the same length."Real Examples of Equilateral Triangles
Below are real examples of equilateral triangles.In each case
- All 3 sides are the same length.
- All 3 angles are the same (60°).
Properties of Equilateral Triangles
The Interior Angles of an Equilateral Triangle
Each interior angle of an equilateral triangle is 60°.The Symmetry of Equilateral Triangles
An equilateral triangle has 3 lines of symmetry.What's in a Name?
'Equilateral' comes from the Latin word "aequilateralis". 'aequi' comes from the word "aequalis", meaning 'equal', and 'lateralis' means 'relating to the side'. 'Equilateral' means 'equal sides'.The Interior Angles of an Equilateral Triangle
The interior angles of any triangle add up to 180°. Since all three angles are the same in an equilateral triangle, the 180° is divided equally between each interior angle.This is why each angle is 60°.
Interactive Game on the Types of Triangle
Here is an interactive game to help you learn about the types of triangle.- Click on a triangle so it drops into the correct "bucket."
- In total, there are 10 triangles to clear.
- If a triangle drops into the wrong "bucket," you will lose one of your three lives.
- Good luck!
Worksheet
This test is printable and sendable