Classifying Triangles

Related Pages
Types Of Triangles
Special Right Triangles
Area Of Triangles
More Geometry Lessons

The following figures show how to classify triangles based on sides and angles. Scroll down the page for more examples and solutions.

Classify Triangles Based On Sides And Angles

Learn to classify triangles based on sides and angles.

Classifying Triangles Song
Learn to classify triangles based on sides and angles.

Lyrics:

Isosceles triangles have two equal sides
like this mountain we’re about to climb;

and since one angle’s over ninety degrees,
an obtuse triangle is what we see.

If you add up every angle,
there are one hundred eighty degrees in a triangle.

If the length is equal on every side,
we say it’s equilateral, like this road sign;

and since every angle’s less than 90 degrees,
an acute triangle it will also be.

If skateboard ramps are your scene,
with three different sides they’re called scalene.

That triangle would also be called right
if a ninety degree angle is inside.

There are two ways to classify triangles:
by their sides and their angles,

like sails out on the high seas
can be right or isosceles.

Or look at the foot of this goose;
it’s scalene and obtuse.

When you break pool balls with a cue,
they’re equilateral and acute.

• Show Video Lesson

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.

We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.