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Warm Up. Problem of the Day. Lesson Presentation. Lesson Quizzes. Warm Up Solve. 1. x + 30 = 90 2. 103 + x = 180 3. 32 + x = 180 4. 90 = 61 + x 5. x + 20 = 90. x = 60. x = 77. x = 148. x = 29. x = 70. 1 3. 1 6. Problem of the Day
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Warm Up Problem of the Day Lesson Presentation Lesson Quizzes
Warm Up Solve. 1. x + 30 = 90 2. 103 + x = 180 3. 32 + x = 180 4. 90 = 61 + x 5. x + 20 = 90 x = 60 x = 77 x = 148 x = 29 x = 70
1 3 1 6 Problem of the Day Mrs. Meyer’s class is having a pizza party. Half the class wants pepperoni on the pizza, of the class wants sausage on the pizza, and the rest want only cheese on the pizza. What fraction of Mrs. Meyer’s class wants just cheese on the pizza?
Sunshine State Standards MA.8.G.2.2 Classify and determine the measure of angles,…
Vocabulary angle adjacent angles right angle supplementary angles acute angle complementary angles obtuse angle straight angle vertical angles congruent angles
An angle () is formed by two rays, or sides, with a common endpoint called the vertex. You can name an angle several ways: by its vertex, by its vertex and a point on each ray, or by a number. When three points are used, the middle point must be the vertex.
Additional Example 1: Classifying Angles Use the diagram to name each figure. A. two acute angles TQP, RQS mTQP = 43°; mRQS = 47° B. two obtuse angles SQP, RQT mSQP= 133°; mRQT = 137°
Additional Example 1: Classifying Angles Use the diagram to name each figure. C. a pair of complementary angles TQP, RQS mTQP + mRQS = 43° + 47° = 90 B. two pairs of supplementary angles TQP, TQR mTQP + mTQR = 43° + 137° = 180 mSQP + mSQR = 133° + 47° = 180 SQP, SQR
Check It Out: Example 1 Use the diagram to name each figure. A. two acute angles AEB measures 58° and DEC measures 58° B. two obtuse angles AEC measures 148° and DEB measures 122°
Check It Out: Example 1 Use the diagram to name each figure. C. a pair of complementary angles AEB measures 58° and DEC measures 32°.58 + 32 = 90° D. a pair of supplementary angles AEC measures 148° and DEC measures 32°. 148 + 32 = 180°; AEB measures 58° and DEB measures 122°, 58 + 122 = 180°
Additional Example 2A: Finding Angle Measures Use the diagram to find each angle measure. If m1 = 37°, find m2. m1 + m2 = 180° 1 and 2 are supplementary. 37° + m2= 180° Substitute 37 for m1. –37° –37° Subtract 37 from both sides. m2 = 143°
Additional Example 2B: Finding Angle Measures Use the diagram to find each angle measure. Find m3 = 37°. m2 + m3 = 180° 2 and 3 are supplementary. 143° + m3 = 180° Substitute 143 for m2. –143° –143° Subtract 143 from both sides. m3 = 37°
Check It Out: Example 2A Use the diagram to find each angle measure. If m3 = 142°, find m4. m3 + m4 = 180° 142° + m4= 180° m4 = 38° –142° –142°
Check It Out: Example 2B Use the diagram to find each angle measure. Find m1. m1 + m4 = 180° m1 + 38° = 180° m1 = 142° –38° –38°
Adjacent angles have a common vertex and a common side, but no common interior points. Angles 1 and 2 in the diagram are adjacent angles. Congruent angleshave the same measure. Vertical angles are the nonadjacent angles formed by two intersecting lines. Angles 2 and 4 are vertical angles. Vertical angles are congruent.
Additional Example 3: Application A traffic engineer designed a section of roadway where three streets intersect. Based on the diagram, what is the measure of DBE. Step 1: Find mCBD. ABFCBD Vertical angles are congruent. Congruent angles have the same measure. mABF= mCBD Substitute 26 for mCBD. mCBD= 26
Additional Example 3 Continued A traffic engineer designed a section of roadway where three streets intersect. Based on the diagram, what is the measure of DBE. Step 2: Find mDBE. mCBD + mDEB = 90° The angles are complementary. 26 + mDEB = 90° Substitute 26 for mCBD. –26° –26° Subtract 26 from both sides. mDEB = 64°
Check It Out: Example 3 Based on the map, what is the measure of BGC? AGB is congruent to EGF. mAGB = 42° mBGC + mAGB = 90° mBGC + 42° = 90° mBGC = 48°
Lesson Quizzes Standard Lesson Quiz Lesson Quiz for Student Response Systems
Lesson Quiz Use the diagram to name each figure or find each angle measure. 1. a right angle Possible answer: CGD 2. two acute angles Possible answer: 1, 2 3. pair of complementary angles Possible answer: 3, 4 4. If m1 = 47°, then find m3. 47° 5. Find m4. 43°
Lesson Quiz for Student Response Systems 1. If m1 = 42°, then find m3. A. 3° B. 42° C.48° D.90°
Lesson Quiz for Student Response Systems 2. Name a pair of complementary angles. A. CGD B. AGF C.AGB, BGC D.CGD, DGF
Lesson Quiz for Student Response Systems 3. Find mCGD. A. 3° B. 42° C.90° D.180°