1. Review: Classifying Triangles and The Triangle Angle Sum Theorem

2. Warm Up
Solve the equations for the unknown variable.
1.)
2.)
3.)

3. Classifying Triangles
Two ways to classify: by their sides; by their angles.
Sides - Scalene, isosceles, equilateral
Angles – Acute, obtuse, right

4. Examples
Name the triangle by it’s sides and angles.

5. Triangle Angle-Sum Theorem
The TAST says that all three angles of any triangle have to add together to equal 180. 40
So, if we are given two of the three angles of a triangle, we can find the third. 90 50

6. Examples
Find the unknown angles. x 60
130 40 60 x

7. Examples
Solve for x.
X+22 20
X+58 90
x+30 70