How Do You Classify Triangles?

Note:

Being able to classify triangles is an important skill. If you know what kind of triangle you're looking at, it's much easier to figure out how to solve for various sides and angles. Practice classifying triangles with this tutorial!

Keywords:

triangle
triangles
classify triangles
angle
angles
isosceles
isosceles triangle
equilateral
equilateral triangle
scalene
scalene triangle
right triangle
obtuse triangle
acute triangle
acute
obtuse
right
side length
sides
side lengths

Background Tutorials

Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
- What is a Line Segment?
  
  A math term can really tell you a lot about the thing it's describing. Take the term line segment. A line segment is just part of a line! In this tutorial, learn about line segments, how to name them, and what the midpoint of a line segment is!
- What is an Angle?
  
  Angles are a fundamental building block for creating all sorts of shapes! In this tutorial, learn about how an angle is formed, how to name an angle, and how an angle is measured. Take a look!
- What are Acute, Obtuse, Right, and Straight Angles?
  
  Did you know that there are different kinds of angles? Knowing how to identify these angles is an important part of solving many problems involving angles. Check out this tutorial and learn about the different kinds of angles!
Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles.
- What is a Triangle?
  
  You can't learn everything about math without dealing with triangles. Did you know that there are different types of triangles? Check out this tutorial, and learn about triangles and their different types!