What is the missing angle in a triangle that has one 80 degree angle and one 20 degree angle?
80 degrees
Acute, obtuse, right

Why is this NOT a triangle?
It's not a closed figure
What is the value of the missing angle here?
65 degrees
Classify this triangle based on side length and angles
Acute equilateral
All angles in triangles need to add to....
Classify this triangle AND find the missing value

Obtuse, 25 degrees
Classify this triangle based on side length and angles. 
Acute scalene
Define an acute triangle and give examples of angle measurements.
3 angles that are all less than 90 degrees and add up to 180 degrees
Why can you not have more than one obtuse angle in a triangle?
Triangles have to add to 180 and need 3 angles. 91+91 > 180.
A triangle with two sides of the same length and two 45 degree angles is called
Right isosceles
Explain why the bottom three are not triangles.
First triangle - more than 3 sides
second - not a closed figure
third - not composed of line segments
What is the value of each angle in this triangle?\

x = 15.
6x = 90
4x = 60
2x = 30
Classify this triangle based on side length and angles
Obtuse isosceles
Define an obtuse scalene triangle and give examples for side length and angle measurements
1 obtuse angle, 2 acute angles
All different side lengths