25
1-6: Algebra and Angles I CAN: Use algebra to solve for unknown angle measures.
1-6: Algebra and AnglesI CAN:Use algebra to solve for unknown angle measures.
Warm Up 1/23/2013 Label each supplementary,
complementary, or neither. 1. 40º + 50º 2. 130º + 50º 3. 45º + 35º 4. 65º + 25º 5. 123º + 62º 6. 145º + 35º 7. 12º + 108º 8. 54º + 36º
Warm Up 1/23/2013 Label each supplementary,
complementary, or neither. 1. 40º + 50º 90º Complementary 2. 130º + 50º 180º Straight 3. 45º + 35º 80º Neither 4. 65º + 25º 90º Complementary 5. 123º + 62º 185º Neither 6. 145º + 35º 180º Straight 7. 12º + 108º 120º Neither 8. 54º + 36º 90º Complementary
WARM UP 1/24/13Identify the complement of each angle.1. 15º 2. 36º 3. 89º
4. 76º
1-5 Quiz Label your paper: Name/Date/Block/1-5 QuizIdentify the complement of each angle.1. 15º 2. 36º 3. 89º 4. 76º5. 24º 6. 47º 7. 87º 8. 1º
Identify the supplement of each angle.9. 63º 10. 101º 11. 56º 12. 28º13. 34º 14. 15º 15. 154º 16. 89º
Find the missing
angles. <H = 35, <E = 55, <G = 45, <B = 4517. A = ____ 18. C = ____ 19. D = ___20. F = ____
AB
CD
EF
GH
Example 1 The measure of one of two
complementary angles is 20º. What is the measure of the second angle?
Example 1 The measure of one of two
complementary angles is 20º. What is the measure of the second angle?
Step 1: Call the unknown angle measure x.
Example 1 The measure of one of two
complementary angles is 20º. What is the measure of the second angle?
Step 1: Call the unknown angle measure x.
Step 2: 20º + x = 90º by definition of complementary angles.
Example 1 The measure of one of two
complementary angles is 20º. What is the measure of the second angle?
Step 1: Call the unknown angle measure x.
Step 2: 20º + x = 90º by definition of complementary angles.
Step 3: x = 90º - 20º … X = 70º
Example 2 The measure of one of two
supplementary angles is 35º. W hat is the measure of the second angle?
Example 2 The measure of one of two
supplementary angles is 35º. W hat is the measure of the second angle?
Step 1: Call the unknown measure y.
Example 2 The measure of one of two
supplementary angles is 35º. W hat is the measure of the second angle?
Step 1: Call the unknown measure y. Step 2: 35º + y = 180º by the definition
of supplementary angles
Example 2 The measure of one of two
supplementary angles is 35º. W hat is the measure of the second angle?
Step 1: Call the unknown measure y. Step 2: 35º + y = 180º by the definition
of supplementary angles Step 3: y = 180º - 35º … y = 145º
Example 3 The measure of one supplementary
angle is twice the measure of the second supplementary angle. What is the measure of each angle?
Example 3 The measure of one supplementary
angle is twice the measure of the second supplementary angle. What is the measure of each angle?
Step 1: Let w be the measure of the smaller angle. Let 2w be the measure of the larger angle.
Example 3 The measure of one supplementary angle is twice
the measure of the second supplementary angle. What is the measure of each angle?
Step 1: Let w be the measure of the smaller angle. Let 2w be the measure of the larger angle.
Step 2: 2w + w = 180º by the definition of supplementary angles.
Example 3 The measure of one supplementary angle is twice
the measure of the second supplementary angle. What is the measure of each angle?
Step 1: Let w be the measure of the smaller angle. Let 2w be the measure of the larger angle.
Step 2: 2w + w = 180º by the definition of supplementary angles.
Step 3: 3w = 180º …. w = 60º
W = 60º
y
x
z
Example 3 The measure of one supplementary angle is twice
the measure of the second supplementary angle. What is the measure of each angle?
Step 1: Let w be the measure of the smaller angle. Let 2w be the measure of the larger angle.
Step 2: 2w + w = 180º by the definition of supplementary angles.
Step 3: 3w = 180º …. w = 60º Step 4: x + 60º = 180º
X = 180º - 60º X = 120º so m<x = 120º
W = 60º
y
x
z
Example 3 The measure of one supplementary angle is twice
the measure of the second supplementary angle. What is the measure of each angle?
Step 1: Let w be the measure of the smaller angle. Let 2w be the measure of the larger angle.
Step 2: 2w + w = 180º by the definition of supplementary angles.
Step 3: 3w = 180º …. w = 60º Step 4: x + 160º = 180º
X = 180º - 60º X = 120º so m<x = 120º
Step 5: y + 60º = 180º Y = 180º - 60º Y = 120º so m<y = 120º
W = 60º
Y
X =120
z
Example 3 The measure of one supplementary angle is twice the
measure of the second supplementary angle. What is the measure of each angle?
Step 1: Let w be the measure of the smaller angle. Let 2w be the measure of the larger angle.
Step 2: 2w + w = 180º by the definition of supplementary angles.
Step 3: 3w = 180º …. w = 60º Step 4: x + 160º = 180º
X = 180º - 60º X = 120º so m<x = 120º
Step 5: y + 60º = 180º Y = 180º - 60º Y = 120º so m<y = 120º
Step 6: z + 120º = 180º Z = 180º - 120º Z = 60º
W = 60º
Y = 120º
X =120
z
Example 3 The measure of one supplementary angle is twice the
measure of the second supplementary angle. What is the measure of each angle?
Step 1: Let w be the measure of the smaller angle. Let 2w be the measure of the larger angle.
Step 2: 2w + w = 180º by the definition of supplementary angles.
Step 3: 3w = 180º …. w = 60º Step 4: x + 160º = 180º
X = 180º - 60º X = 120º so m<x = 120º
Step 5: y + 60º = 180º Y = 180º - 60º Y = 120º so m<y = 120º
Step 6: z + 120º = 180º Z = 180º - 120º Z = 60º
W = 60º
Y = 120º
X =120
Z = 60º
Think-Pair-Share Complete the problem that matches the
color of post it that you received… Complete on loose leaf…
Pink: The measure of one of two complementary angles equals 30º. What is the measure of the second angle?
Blue: The measure of one of two supplementary angles equals 30º. What is the measure of the second angle?
Orange: The measure of one of two supplementary angles is 3 times larger than the other. What are the measures of the angles?
Think-Pair-Share Complete the problem that matches the color of
post it that you received… Complete on loose leaf…
Pink: The measure of one of two complementary angles equals 30º. What is the measure of the second angle?
Blue: The measure of one of two supplementary angles equals 30º. What is the measure of the second angle?
Orange: The measure of one of two supplementary angles is 3 times larger than the other. What are the measures of the angles?
**Now – Find the person with the matching post it. Compare your answers and determine a method for teaching the class your problem**
Independent Assignment 30 Minutes Pages 26-27 All
Closure Homework: Workbook Activity 7 Parking Lot Post It Tomorrow: Review Friday: Chapter 1 Test
