1. WELCOME BACK 1. Please pick up your SKILL BUILDER and WEEKLY HOMEWORK. 2. Turn in your EXTRA CREDIT along with your Builder 28 to the tray. 3. COPY DOWN THE AGENDA for the WEEK. TEST FRIDAY!!! 3. Please complete the first 2 sections of your SKILL BUILDER now.

2. -7c + 5 -6f + 5 18c + 24 -8g - 6 x -22 x 20

3. Identify each pair of angles as complementary, supplementary, or neither. 1. 2. 3. 4. Write and solve an equation to determine the value of x. 5. Tell whether the following statement is true or false. Angles are complementary if the sum of their measures is 180°.

4. Triangle Sum Theorem The sum of the measures of the interior angles of a triangle is 180 o. 3 2 1 m<1 + m<2 + m<3 = 180°

5. The sum of all the angles equals 180º degrees. 90º 30º 60º 90º 30º + 180º Property of triangles

6. 90º 50º 40º 90º 50º + 180º The sum of all the angles equals 180º degrees. Property of triangles

7. 60º + 180º 60º The sum of all the angles equals 180º degrees. Property of triangles

8. Ex: 1What is the missing angle? 70º x + 180º 70º x 180 – 140 = 40˚

9. 90º 30º x + 180º 30º 90º x 180 – 120 = 60˚ EX: 2 What is the missing angle?

10. 60º x + 180º 60º x 180 – 120 = 60˚ Ex: 3What is the missing angle?

11. 30º 78º X + 180º 78º 30º X 180 – 108 = 72˚ EX 4: What is the missing angle?

12. 40º ? + 180º 40º ? 180 – 80 = 100˚ What is the missing angle?

13. 45x 10x 35x 90°, 70°, 20° Find all the angle measures 180 = 35x + 45x + 10x 180 = 90x 2 = x

14. What can we find out? The ladder is leaning on the ground at a 65º angle. At what angle is the top of the ladder touching the building? 180 = 65 + 90 + x 180 = 155 + x 25˚ = x

15. Extention to Triangle Sum Theorem The acute angles of a right triangle are complementary. m ∠ A + m ∠ B = 90 o

16. The tiled staircase shown below forms a right triangle. The measure of one acute angle in the triangle is twice the measure of the other angle. Find the measure of each acute angle. Find the missing angles. Con’t

17. Find the missing angles. 2x + x = 90 3x = 90 x = 30˚ 2x = 60˚ SOLUTION:

18. Find the missing angles. 2x + (x – 6) = 90˚ 3x – 6 = 90 3x = 96 x = 32 2x = 2(32) = 64˚ (x – 6) = 32 – 6 = 26˚

19. Example: Find x and the measure of each angle. C A B

20. Example: Find x and the measure of each angle. C A B

21. Example: Find x and the measure of each angle. C A B

22. Example: Refer to the diagram below to complete the table. 2 3 14

23. Find the value of x.

24. The measures of three angles of a triangle are given by (8x  5)°, (2x)°, and (3x  10)°. What is the measure of the largest angle?

25. TRIANGLE SUM THEOREM This packet is due Thursday. Please complete # 1-16 tonight for homework as well as your Weekly Homework.