1. Chapter 5 Lesson 3 Angles of Triangles

2. Solve each equation for x. 1.) 2.)
Bellwork
Solve each equation for x.
1.)
2.)

3. What are Interior & Exterior Angles?
Interior Angles are angles inside a polygon.
Exterior Angles are the angles outside of the polygon that are adjacent to the interior angles.

4. Interior Angle Measures of a Triangle
The sum of the interior angle measures of a triangle is 1800
Algebra
x+y+z=180

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

6. c.

7. Practice 81+25+x=180 106+x=180 x=740 Find the value of x.

8. Practice

9. Try this with a partner!

10. On your own this time!

11. Exterior Angle Measures
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

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

13. 1..

14. 2.

15. Find the measure of the exterior angle.
4n-20=n+2n+20 4n-20=3n+20 n-20=20 n=40 Exterior angle= 4(40)-20=160-20=1400
y=40+30 y=700

16. Use Your Algebra Skills

17. 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.

18. Guided Practice pg. 392 (1-5)

21. Independent Practice

23. Exit Ticket