1. 10/26 WORKBOOK WARM UP
Exploring Interior Angles of Triangles– Open your workbooks to P. 351 EXPLORE: A-C!!!
Parts A – H

2. 7.1 INTERIOR & EXTERIOR ANGLES OBJECTIVE
I can verify theorems about triangles, including the sum of interior angles. (G.6D)

3. Triangle Sum Theorem
The sum of the interior angles of a triangle is 180.
TAKE NOTES

4. TRIANGLE SUM THEOREM PROOF

5. STATEMENT REASON 1. Draw line ℓ through point B parallel to A_C .
1. Parallel Postulate
2. m∠1 = m∠ __ and m∠3 = m∠ __
2. ___________________
3. m∠4 + m∠2 + m∠5 = 180°
3. Angle Addition Postulate & definition of straight angle
4. m∠ __ + m∠2 + m∠ __ = 180°
4. ____________________
P. 321

6. EXPLORING INTERIOR ANGLES OF POLYGONS
Have students tear out
***check their boxes for orderly books before they leave

7. POLYGON # OF SIDES # OF TRIANGLES SUM OF INTERIOR ANGLES Triangle 3 1
Quadrilateral 4 2
Pentagon 5
Hexagon 6
Decagon 10 8
P. 352 – 353
PART C - Do you notice a pattern between the number of sides and the number of triangles?

8. POLYGON ANGLE SUM THEOREM
The sum of the measures of the interior angles of a convex polygon with n sides is: (n – 2) 180°
Have students complete in workbooks
P. 353

9. I DO, YOU WATCH
Determine the unknown angle measures. A) For the nonagon shown, find the unknown angle x°.
Have students complete in workbooks
P. 354

10. Determine the unknown angle measures in this pentagon. 6)
I DO, YOU HELP
Determine the unknown angle measures in this pentagon. 6)
Have students complete in workbooks
P. 354

11. P. 355 #S 7 & 8 YOU DO, I HELP Have students complete in workbooks

12. EXTERIOR & REMOTE ANGLES
Exterior Angle – The outside angle of a triangle Remote Angles – Interior angles not adjacent to the exterior angle
Have students complete in workbooks
P. 354

13. EXTERIOR ANGLES THEOREM
The measure of an exterior angle of a triangle is equal to the sum of the measures of its remote interior angles.
Have students complete in workbooks
P. 355

14. EXTERIOR & REMOTE ANGLES
Have students complete in workbooks
P. 355

15. REFLECT #9! P. 356
Determine the measure of each exterior angle. Add them together. What can you say about their sum? Explain.

16. Determine the measure of the specified angle. A) For angle B
I DO, YOU WATCH
Determine the measure of the specified angle. A) For angle B
Have students complete in workbooks
P. 357

17. Determine the measure of the specified angle. B) Find m∠PRS.
I DO, YOU HELP
Determine the measure of the specified angle. B) Find m∠PRS.
Have students complete in workbooks
P. 354

18. P. 358 #S 11 & 12 YOU DO, I HELP Have students complete in workbooks

19. HW#2: 7.1 P. 360-362 #S 5-15 ODD DUE TOMORROW
Have students tear out
***check their boxes for orderly books before they leave