Triangles

A Guided PowerPoint Presentation

15cm

5cm10cm94º 1.

A SCALENE TRIANGLEand

AN OBTUSE TRIANGLE

The reason is: there is an obtuse angle at the top part of the

triangle, and all three sides have different measurements.

Obtuse angle

Obtuse angle

3in.

3in.

2.

The Right Triangleor

An Isosceles Triangle

This triangle has a right angle and two sides that are congruent.

3.

Right again, and also Scalene.Why?

The rectangle in the lower left angle makes it RIGHT. Can you see that all three sides are different in length?

What could this be?

• Two sides are congruent and all the angles are smaller than 90º.

4.

It is a scalene triangle and an...

Acute Triangle!!!!

? ? ? ? ? ? ?

5.

Acute and Equilateralbecause…..

All sides are congruent and all the angles are 60º.

The complete triangle on the right has 3 angles. If we cut off two angles and line them up to the third angle, it creates a 180º angle.

Remember, three angles of every triangle equal 180º.

a

ab

b

What type is this one??

6.

Four sides can’t be a triangle. It has to be a quadrilateral.