Classify Triangles Worksheets

Printable “Geometry” Worksheets:
Types of Angles
Lines of Symmetry
Classify Triangles

Classify Triangles Worksheets

In these free math worksheets, students analyze and classify triangles based on side length, angle measure, or both.

How to classify triangles?
Triangles can be classified based on the length of their sides and the size of their angles.
Here are the common classifications:

Based on the length of the sides:

• Scalene triangle: A triangle with no equal sides.
• Isosceles triangle: A triangle with two equal sides.
• Equilateral triangle: A triangle with three equal sides.

Based on the size of the angles:

• Acute triangle: A triangle with all three angles less than 90 degrees.
• Right triangle: A triangle with one angle equal to 90 degrees.
• Obtuse triangle: A triangle with one angle greater than 90 degrees.

Combining the two classifications, we can have more specific classifications such as:

• Right isosceles triangle: A triangle with one angle equal to 90 degrees and two equal sides.
  
• Obtuse scalene triangle: A triangle with one angle greater than 90 degrees and no equal sides.
  
• Acute equilateral triangle: A triangle with all three angles less than 90 degrees and three equal sides.

Have a look at this video if you need to review how to classify by sides and angles.

• How to Name Triangles (by Sides and Angles)

Click on the following worksheet to get a printable pdf document.
Scroll down the page for more Classify Triangles Worksheets.

 

More Classify Triangles Worksheets

Printable
Classify Triangles Worksheet #1
(Answers on the second page.)
Classify Triangles Worksheet #2
(Answers on the second page.)

Analyze Triangles Word Problems

1. A triangle cannot have one obtuse angle and one right angle. True or False?
   • Show Answer

     True

2. An equilateral triangle is isosceles. True or False?
   • Show Answer

     True

3. Every triangle has at least ____ acute angles.
   • Show Answer

     Two

4. A triangle cannot have both an acute angle and a right angle. True or False?
   • Show Answer

     False

5. A right triangle is always scalene. True or False?
   • Show Answer

     False

Related Lessons & Worksheets

Classify Triangles Lesson

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