370 likes | 508 Views
Lesson 9.4 Inscribed Angles pp. 390-393. Objectives: 1. To identify and prove theorems relating inscribed angles to the measure of their intercepted arcs. 2. To state other relationships that involve inscribed angles. Theorem 9.13
E N D
Lesson 9.4 Inscribed Angles pp. 390-393
Objectives: 1. To identify and prove theorems relating inscribed angles to the measure of their intercepted arcs. 2. To state other relationships that involve inscribed angles.
Theorem 9.13 The measure of an inscribed angle is equal to one-half the measure of its intercepted arc.
A K C B
A K B D C
A C B D K
B O C A If mAC = 60, then mABC = 30.
Theorem 9.14 If two inscribed angles intercept congruent arcs, then the angles are congruent.
B O D C A ABC ADC
Theorem 9.15 An angle inscribed in a semicircle is a right angle.
O A C B mABC = 90.
Theorem 9.16 The opposite angles of an inscribed quadrilateral are supplementary.
D O A C B ABC and ADC are supplementary. BAD and BCD are supplementary.
Given: In circle M, mRT = 80, mSQ = 64. Find mQTS. R Q U M T S P
Given: In circle M, mRT = 80, mSQ = 64. Find mTQR. R Q U M T S P
Given: In circle M, mRT = 80, mSQ = 64. Find mTQP. R Q U M T S P
Given: In circle M, mRT = 80, mSQ = 64. Find mTPR. R Q U M T S P
A B K D C E Given: In circle K, AB || DE, AC BC; mBAC = 56°. Find mAC.
A B K D C E Given: In circle K, AB || DE, AC BC; mBAC = 56°. Find mBC.
A B K D C E Given: In circle K, AB || DE, AC BC; mBAC = 56°. Find mACB.
A B K D C E Given: In circle K, AB || DE, AC BC; mBAC = 56°. Find mABC.
A B K D C E Given: In circle K, AB || DE, AC BC; mBAC = 56°. Find mAB.
Homework pp. 392-393
►A. Exercises 1. If mDC = 60°, find m4. D C X 1 2 3 4 O A B
►A. Exercises 3. If m3 = 25°, find mDC. D C X 1 2 3 4 O A B
D C X 1 2 3 4 O A B ►A. Exercises 5. If m3 = 28°, find m4.
►A. Exercises 7. If mDC = 55°, find mDBC. D C X 1 2 3 4 O A B
►A. Exercises 9. If mADB = 290°, find m1. D C X 1 2 3 4 O A B
►B. Exercises 11. If mDC = 68° and mAB = 134°, find mDXA. D C X 1 2 3 4 O A B
►B. Exercises Use the following figure for exercises 12-16. 13. If mMLO = 240°, find mMLO. M L P Y N O
►B. Exercises Use the following figure for exercises 12-16. 15. If mMLO = 212°, find mMNO and mMLO. M L P Y N O
■ Cumulative Review Justify each statement with a reason. Given: ABC is obtuse; CD AB at D E C A D B 27. CDA and CDB are right angles.
■ Cumulative Review Justify each statement with a reason. Given: ABC is obtuse; CD AB at D E C A D B 28. BC BD
■ Cumulative Review Justify each statement with a reason. Given: ABC is obtuse; CD AB at D E C A D B 29. mACE = mB + mCAD
■ Cumulative Review Justify each statement with a reason. Given: ABC is obtuse; CD AB at D E C A D B 30. AE + AB BE
■ Cumulative Review Justify each statement with a reason. Given: ABC is obtuse; CD AB at D E C A D B 31. mBAE + mABE + mE = 180°