How can you classify these different triangles?

In this lesson you will learn how to classify triangles by observing

their angles.

Let’s Review

An angle is a figure made from two rays that have the same endpoint.

Angle

Let’s Review

Angles are given special names depending on their size.

Right Obtuse Acute Straight

Let’s Review

A triangle is a polygon with three sides and three angles.

Core Lesson

We can classify and sort triangles by the types of angles that make them up.

Acute TrianglesRight Triangles Obtuse Triangles

G

Core Lesson

Right triangles are triangles with one right angle and two acute angles.

Core Lesson

Acute triangles are triangles with all acute angles.

Core Lesson

Obtuse triangles are triangles with one obtuse angle and two acute angles.

Core Lesson

Sorting by angle types.

Right Triangles Acute Triangles Obtuse Triangles

Core Lesson

What type of triangle is formed on the inside of these stairs?

Right Triangle

Core Lesson

What type of triangle is this slice of pizza ?

Acute Triangle

Core Lesson

What type of triangle is the roof of this house?

Obtuse Triangle

Core Lesson

Acute Triangle Obtuse Triangle Right Triangle

How can you classify these different triangles?

In this lesson you have learned how to classify triangles by observing

their angles.