1.  3.2: Angles of Triangles

2. What are Interior and Exterior Angles  Interior Angles are angles inside a polygon.  When the sides of a polygon are extended, other angles are formed.  Exterior Angles are the angles outside of the polygon that are adjacent to the interior angles.

3. Interior Angles Measures of a Triangle  The sum of the interior angle measures of a triangle is 180 0  Algebra  x+y+z=180

4. Using Interior Angle Measures Find the value of x.

5. Practice  43+x+x-35=180 2x+8=180 2x=172 x=86 0  81+25+x=180 106+x=180 x=74 0 Find the value of x.

6. Exterior Angle Measures of a Triangle  The measure of an exterior angle of a triangle is equal to the sum of the measures of the two nonadjacent interior angles.  Algebra  z=x+y

7. Finding Exterior Angle Measures Find the measure of the exterior angle.

8. Practice  4n-20=n+2n+20 4n-20=3n+20 n-20=20 n=40 Exterior angle= 4(40)-20=160-20=140 0  y=40+30 y=70 0 Find the measure of the exterior angle.

9. Real Life Application  An airplane leaves from Miami and travels around the Bermuda Triangle. What is the value of x?  Use what you know about the interior angle measures of a triangle to write an equation.