What type of triangle has three equal sides?
Triangles have three sides and three angles. Triangles can be classified by their sides or angles. Knowing how to classify triangles helps us understand their properties.
Classifying Triangles
Equilateral Triangle: A triangle with all sides equal in length. Isosceles Triangle: A triangle with two sides equal in length. Scalene Triangle: A triangle with all three sides having different lengths.
Concepts:
The first use of the word “triangle” was in a book written by Euclid, an ancient Greek mathematician, around 300 BCE. The sum of the angles of a triangle is always 180°, no matter the size or shape. The area of a triangle can be calculated using Heron’s Formula, which is named after an ancient Greek mathematician.
Fun facts:
Work together in pairs: Which type of triangle did you find the most interesting to learn about during this lesson? Explain why.
Work together in pairs: What are the three main ways to classify a triangle?
Brain break: Draw a self-portrait of yourself as a superhero!
What type of triangle has three sides that are equal in length?
- Scalene
- Isosceles
- Equilateral
- Right
What type of triangle has two sides that are equal in length?
- Scalene
- Isosceles
- Equilateral
- Right
What type of triangle has three angles that are equal in measure?
- Scalene
- Isosceles
- Equilateral
- Right
What type of triangle has one angle that is 90 degrees?
- Scalene
- Isosceles
- Equilateral
- Right
What type of triangle has two angles that are equal in measure?
- Scalene
- Isosceles
- Equilateral
- Right