alternate interior angles alternate exterior angles Identify special pairs of angles and relationships of angles formed by two parallel lines cut by a transversal. vertical angles interior angles exterior angles alternate interior angles alternate exterior angles corresponding angles complementary angles supplementary angles perpendicular lines parallel lines transversal Main Idea/Vocabulary
KC 1
Find a Missing Angle Measure The two angles below are supplementary. Find the value of x. 155 + x = 180 Write an equation. = Subtract 155 from each side. Simplify. Answer: 25 Example 1
The two angles below are complementary. Find the value of x. A. 35 B. 40 C. 45 D. 50 Example 1
Find a Missing Angle Measure Find the value of x in the figure. Use the two vertical angles to solve for x. 68 + x = 90 Write an equation. – 68 =– 68 Subtract 68 from each side. x = 22 Simplify. Answer: 22 Example 2
Find the value of x in the figure. B C D A. 20 B. 25 C. 30 D. 70 Example 2
KC 2
Since 3 and 5 are alternate interior angles, they are congruent. Find an Angle Measure BRIDGES The drawing shows a simple bridge design. The top beam and the floor of the bridge are parallel. If 2 3 and m3 = 55, classify the relationship between 1 and 5. Then find m1 and m5. Since 3 and 5 are alternate interior angles, they are congruent. Also, since 1 and 2 are supplementary, 1 and 3 are supplementary, and 1 and 5 are supplementary. Example 3
Since 3 and 5 are alternate interior angles, m5 = 55. Find an Angle Measure Since m3 = 55 and 2 3, m2 = 55. Since 3 and 5 are alternate interior angles, m5 = 55. Since 1 and 2 are supplementary, the sum of their measures is 180. Therefore, m1 = 180 − 55 or 125. Answer: They are supplementary; m1 = 125° and m5 = 55°. Example 3
BRIDGES The sketch below shows a simple bridge design BRIDGES The sketch below shows a simple bridge design. The top beam and floor of the bridge are parallel. If m1 = 45° and m3 = 40°, find m4. A B C D A. 85° B. 95° C. 100° D. 105° Example 3
Write 7 out of 20 as a percent. (over Chapter 5) Write 7 out of 20 as a percent. A. 0.035% B. 0.35% C. 3.5% D. 35% A B C D Five Minute Check 1
Express 48% as a fraction in simplest form. (over Chapter 5) Express 48% as a fraction in simplest form. A. B. C. D. A B C D Five Minute Check 2
9.5 is 95% of what number? A. 1 B. 9 C. 10 D. 100 (over Chapter 5) A B Five Minute Check 3
(over Chapter 5) Find the percent of change from 15 to 18. State whether the percent of change is an increase or a decrease. A. 20%; decrease B. 20%; increase C. 16.7%; decrease D. 16.7%; increase A B C D Five Minute Check 4
(over Chapter 5) A grocery store manager prices items 30% above their cost. If the manager pays $0.90 per pound for strawberries, what price will he put on the strawberries? A. $11.70/pound B. $3/pound C. $2.70/pound D. $1.17/pound A B C D Five Minute Check 5
(over Chapter 5) Susan deposited $210 to open a savings account that pays 4.7% simple interest annually. If there are no other deposits or withdrawals from the account, how much will be in the account in 24 months? A. $19.74 B. $20.20 C. $229.74 D. $230.20 A B C D Five Minute Check 6
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