Course: 7th Grade Math DETAIL LESSON PLAN Student Objective 7.G.5 Use facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple equations for an unknown angle in a figure. Lesson 8.3.1 – Replacement Lesson Angles and Pairs of Angles Prior Knowledge Review bellwork Review homework Anticipatory Set / Introduction TODAY, we will use those skills to help us classify different types of angles. “Angel” songs. Say… As an introduction to today’s lesson I would like to play a few songs. Listen to the songs and tell me what they all have in common. Play pieces of songs that all mention the word “Angel”. Tell them not to shout out the answer because it may take some a few songs before they figure it out. When ready, call on a student or have students answer together, They all deal with _________? Answer: They all deal with “Angels!” Today, I have been inspired to title our lesson “The Angel of Angles”. Display, “The Angel of Angles” Where do we see Angles? Well… Let’s see… Continue with PowerPoint. Teacher Input Play Angel songs and show PowerPoint (The Angel of Angles) to introduce today’s lesson on angles. Pass out student notes. Define different types of angles: Right, Straight, Acute, Obtuse (Tree Map) Talk about how you measure and draw angles with a protractor. Move on to “Pairs of Angles”. Ask students how many a “pair” is. They should say 2. Discuss these pairs of angles: Complementary, Supplementary, Vertical, and Adjacent Complementary Trick: Starts with a “C”. Draw a “C” on the board. The “C” can be turned into a number. Supplementary Trick: Starts with a “S”. Draw a “S” on the board. The “S” can be turned into a number. Explain and demonstrate how to use what you have just learned about angles to find the measurements of missing angles. Allow students to work the “you try” problems. (Independently) Classwork: Practice sheets involving angles. (In Groups or Think, Pair, Share) Assessment Question students for understanding. Monitor students as they work on their classwork. Closure What is an acute angle? Less than 90 degrees What is an obtuse angle? More than 90 degrees but not 180 degrees How many degrees is a straight line? 180 How many degrees is a right angle? 90 Complementary angles together equal how may degrees? (Think of corner) 90 Supplementary Angles together equal how many degrees? (Think straight line) 180 Vertical angles are _____________? Equal Describe what adjacent angle are. Angles that are next to each other. They share a side. Student Notes Angles Lesson 8.3.1 Section 1 – Angle Types Angle Types Right Angle Measures exactly 90° Straight Angle Measures exactly 180° Acute Angle Measures less than 90° Obtuse Angle Measures greater than 90° Draw your own example of the following angles without a protractor: Acute Angle Right Angle Straight Angle Obtuse Angle Section 2 – Measuring and Drawing Angles Protractors have two sets of numbers going in opposite directions. Be careful which ones you use! When in doubt, think… Should this angle be bigger or smaller than 90º ?” 1) Use a protractor to measure the following angles: a. This is an acute angle. We know that acute angles are smaller than 90°. Which scale should we use to measure our angle? top -or- bottom What is the measurement? Answer: __________ b. This is an obtuse angle. We know that obtuse angles are bigger than 90°. Which scale should we use to measure our angle? top -or- bottom What is the measurement? Answer: __________ 2) Draw the following angles using a protractor. Identify the type of angle you drew. a. 75° b. 160° c. 90° Section 3 – Pairs of Angles Complementary Angles – Two angles that add together to equal exactly 90° Tip! Complementary Angles make a Corner. Supplementary Angles – Two angles that add together to equal exactly 180° Tip! Supplementary Angles make a Straight Line Adjacent Angles – Angles that are next to one another. They share a side. A and B are adjacent angles. Vertical Angles – Angles that are across from one another (or opposite). Vertical angles have equal measurements. A and B are vertical angles. D and C are vertical angles. Angles and Pairs of Angles Guided Practice Use facts about supplementary, complementary, vertical and adjacent angles to find the missing measurements (m). Example 1. Supplementary angles (180ᵒ) Example 2. Complementary angles (90ᵒ) m YNB = _________ m TNB = 106 m BTZ = _________ m ZTG = 49 Example 3. Vertical angles m ZKF = 96º m EKU m UKF m EKZ = _________ = _________ = _________ Example 4 – Measuring Angles. This is an obtuse angle. We know that obtuse angles are bigger than 90°. Which scale should we use to measure G? top -or- bottom What is the measurement of G? Answer: __________ Angles and Pairs of Angles You Try! Use facts about supplementary, complementary, vertical and adjacent angles to find the missing measurements (m). 1. 2. m SEN = _________ m ZEN = 148 m SGU = _________ m UGX = 29 3. m m m m KTS = 81º QTV = _________ KTQ = _________ VTS = _________ 4. m W = _________ W Name: ________________ Period: _____ Angles and Pairs of Angles 1) Classify each angle as acute, obtuse, right, or straight. 2) Find the measure of the complement of each angle. 3) Find the measure the supplement of each angle. 4) Use what you know about vertical and supplement angles to find each missing angle. 5) Answer the following questions about adjacent angles. a) Name two angles adjacent to BAF. ________ ________ b) Name two angles adjacent to KAL. ________ ________ c) Name two angles adjacent to JAM. ________ ________ Name: ___________________ Period: _______ 1. Angles and Angle Pairs A 2. A B m ∠ABC C B m ∠Z ______________° Z ______________° 3. Using what you know about angles to match each measurement to the correct angle. 30º __________° 90º 180º __________° 160º 110º __________° 4. What angle measure is complementary to 73º? ______________° 5. What angle measure is supplementary to 56º? ______________° __________° __________° See Back Use the diagram below to answer questions 6 – 11. E D 45º 45º A F 60° 30º B C 6. Which angle is obtuse? A. ∠FBC B. ∠DBA C. ∠DBC D. ∠EBC 7. Which angle is acute? A. ∠DBE B. ∠ABC C. ∠DBF D. ∠CBE 8. Which angle is complementary to ∠EBF ? A. ∠DBE B. ∠FBC C. ∠DBF D. ∠CBE 9. Which angle is supplementary to ∠ABD ? A. ∠ABC B. ∠FBC C. ∠DBF D. ∠DBC 10. Name a straight angle? ∠____________________ 11. Name two right angles? ∠____________________ 12. Name an angle adjacent to ∠FBC ∠ ∠____________________ ____________________ Answer Key Angles and Pairs of Angles 1) Classify each angle as acute, obtuse, right, or straight. 2) Find the measure of the complement of each angle. 3) Find the measure the supplement of each angle. 4) Use what you know about vertical and supplement angles to find each missing angle. Angles and Angle Pairs Answer Key 1. A 2. A B C B m ∠ABC __120°___ Z m ∠Z ___25° __ 3. Using what you know about angles to match each measurement to the correct angle. 30º ____30____° 90º ___160____° 180º 160º 110º ___180____° ___110____° ____90____° 4. What angle measure is complementary to 73º? ___17____° 5. What angle measure is supplementary to 56º? ___124___° See Back Use the diagram below to answer questions 6 – 11. E D 60° 45º 45º A 6. 8. F 30º B C Which angle is obtuse? A. ∠FBC 7. Which angle is acute? A. ∠DBE B. ∠DBA B. ∠ABC C. ∠DBC C. ∠DBF D. ∠EBC D. ∠CBE Which angle is complementary to ∠EBF ? A. ∠DBE 9. Which angle is supplementary to ∠ABD ? A. ∠ABC B. ∠FBC B. ∠FBC C. ∠DBF C. ∠DBF D. ∠CBE D. ∠DBC 10. Name a straight angle? ∠ABC (sample answer) 11. Name two right angles? ∠EBC , 12. Name an angle adjacent to ∠FBC ∠EBF ∠EBA