Classifying Triangles by Angles (version 2)

There are 4 classifications of triangles by angles. You are probably familiar with them, but glance at the following applets if you need a reminder.

Acute Triangles

Acute Triangles

As you drag point B, notice the angles of the triangle. How would you define an acute triangle?

Obtuse Triangles: For this triangle, you can drag the slider to enlarge the triangle or vertex A to change the shape.

Obtuse Triangles

What do you notice about the angles in the triangle? Using those observations, how would you define an obtuse triangle?

Right Triangles

For this triangle, you can drag the slider to enlarge the triangle or the blue dot to change the shape.

Right Triangles

What stayed the same no matter how you changed the triangle? How would you define a right triangle?

Drag the blue point on the triangle until you have two angles that both measure 45 degrees. This triangle has a special name: isosceles right triangle. What could you say about the lengths of two sides of an isosceles right triangle?

Equiangular Triangle

Use the slider to adjust the size of the triangle.

Equiangular Triangle

Equiangular Triangle

How would you define an equiangular triangle?

What is another name for this type of triangle (think back to your previous exploration).