1. A triangle with three equal angles or sides is an equilateral triangle. Triangles are all 60 degrees.

2. A triangle with two equal angles is called an isosceles triangle. The opposite sides of two equal angles are equal.

A triangle with an angle of 3.90 degrees is equivalent to a right triangle. The formula is that the square of a+the square of b equals the square of C.

4. A triangle with an angle greater than 90 degrees is an obtuse triangle.

That's all primary school math should be. If you have anything to add, please contact me.