Classifying Triangles

Classifying Triangles by Their Side Lengths

By Ms. Genovese

A triangle is an EQUILATERAL triangle when all three of its sides are the same length.

EQULATERAL

A triangle is an ISOSCELES triangle when two of its sides have the same length and one is different.

ISOSCELES

A triangle is a SCALENE triangle if all three of its sides are different lengths.

SCALENE

Go to Next Slide

Follow the link on the next slide to watch the Khan Academy video on classifying triangles by sides.

Khan Academy

You can open this webpage in a new tab.

Copy link

Open in new tab

Use what you have learned to name the following triangles based on their side lengths.

​

Let's Practice!

Multiple Choice

Name this triangle based on its side lengths.

• Equilateral

• Isosceles

• Scalene

Multiple Choice

Name this triangle based on its sides.

• Equilateral

• Isosceles

• Scalene

Multiple Choice

Name this triangle based on its side lengths.

• Equilateral

• Isosceles

• Scalene

Multiple Choice

Name the triangle based on its side lengths.

• Equilateral

• Isosceles

• Scalene

Multiple Choice

Name the triangle based on its side lengths.

• Equilateral

• Isosceles

• Scalene

Multiple Choice

Name this triangle based on its side lengths.

• Equilateral

• Isosceles

• Scalene

Classifying Triangles by Their Angles

By Ms. Genovese

An ACUTE angle is an angle that is SMALLER or OPEN LESS THAN a right angle.

ACUTE ANGLE

A RIGHT angle is an angle that is EXACTLY 90 degrees (a square corner). The corner of a piece of paper can fit perfectly into a right angle.

RIGHT ANGLE

An OBTUSE angle is an angle that is BIGGER or OPEN MORE THAN a right angle.

OBTUSE ANLGE

A triangle is an ACUTE triangle when it has EXACTLY 3 acute angles.

ACUTE TRIANGLE

A triangle is a RIGHT triangle when it has EXACTLY 1 right angle (one square corner).

RIGHT TRIANGLE

A triangle is an OBTUSE triangle if it has EXACTLY 1 obtuse angle.

OBTUSE TRIANGLE

Go to Next Slide

Follow the link on the next slide to watch the Khan Academy video on classifying triangles by angles.

Khan Academy

You can open this webpage in a new tab.

Copy link

Open in new tab

Use what you have learned to name the following triangles based on their side angle measures.

​

Let's Practice!

Multiple Choice

Name this triangle based on its angles.

• Right Triangle

• Acute Triangle

• Obtuse Triangle

Multiple Choice

Name this triangle based on its angles.

• Right Triangle

• Acute Triangle

• Obtuse Triangle

Multiple Choice

Name this triangle based on its angles.

• Right Triangle

• Acute Triangle

• Obtuse Triangle

Multiple Choice

Name this triangle based on its angles.

• Right Triangle

• Acute Triangle

• Obtuse Triangle

Multiple Choice

Name this triangle based on its angles.

• Right Triangle

• Acute Triangle

• Obtuse Triangle

Multiple Choice

Name this triangle based on its angles.

• Right Triangle

• Acute Triangle

• Obtuse Triangle

​Complete the Following

• Complete the EXIT TICKET. This will be your grade today. Turn it in to the PINK BIN when finished. This is INDEPENDENT.

• Work on the worksheets in the triangle practice packet. You may work on the practice packet with a buddy if you like.

• If you finish early, you may read, draw, go on Boddle or go on Legends of Learning.