1. If a triangle has an angle of 90 degrees, what is it called?

2. If a triangle has an angle of 120 degrees, what is it called?

3. If a triangle has an angle of 45 degrees, what is it called?

4. What is the third angle for the triangle where angle1 = 80° and angle2 = 40°?

5. Which of the following triangles are always similar?