Section 10-4
                          Inscribed Angles




Thursday, May 17, 2012
Essential Questions



                How do you find measures of inscribed angles?



                How do you find measures of angles on inscribed polygons?




Thursday, May 17, 2012
Vocabulary

      1. Inscribed Angle:



      2. Intercepted Arc:




Thursday, May 17, 2012
Vocabulary

      1. Inscribed Angle: An angle made of two chords in a circle, so that
       the vertex is on the edge of the circle


      2. Intercepted Arc:




Thursday, May 17, 2012
Vocabulary

      1. Inscribed Angle: An angle made of two chords in a circle, so that
       the vertex is on the edge of the circle


      2. Intercepted Arc: An arc with endpoints on the sides of an
       inscribed angle and in the interior of the inscribed angle




Thursday, May 17, 2012
Theorems

      10.6 - Inscribed Angle Theorem:



      10.7 - Two Inscribed Angles:



      10.8 - Inscribed Angles and Diameters:




Thursday, May 17, 2012
Theorems

      10.6 - Inscribed Angle Theorem: If an angle is inscribed in a circle,
       then the measure of the angle is one half the measure of the
       intercepted arc

      10.7 - Two Inscribed Angles:



      10.8 - Inscribed Angles and Diameters:




Thursday, May 17, 2012
Theorems

      10.6 - Inscribed Angle Theorem: If an angle is inscribed in a circle,
       then the measure of the angle is one half the measure of the
       intercepted arc

      10.7 - Two Inscribed Angles: If two inscribed angles of a circle
       intercept the same arc or congruent arcs, then the angles are
       congruent

      10.8 - Inscribed Angles and Diameters:




Thursday, May 17, 2012
Theorems

      10.6 - Inscribed Angle Theorem: If an angle is inscribed in a circle,
       then the measure of the angle is one half the measure of the
       intercepted arc

      10.7 - Two Inscribed Angles: If two inscribed angles of a circle
       intercept the same arc or congruent arcs, then the angles are
       congruent

      10.8 - Inscribed Angles and Diameters: An inscribed angle of a
       triangle intercepts a diameter or semicircle IFF the angle is a right
       angle

Thursday, May 17, 2012
Example 1
                         Find each measure.
        a. m∠YXW




                
           b. m XZ




Thursday, May 17, 2012
Example 1
                         Find each measure.
        a. m∠YXW

                 1 
          m∠YXW = mYW
                 2


                
           b. m XZ




Thursday, May 17, 2012
Example 1
                         Find each measure.
        a. m∠YXW

                 1  1
          m∠YXW = mYW = (86)
                 2     2


                
           b. m XZ




Thursday, May 17, 2012
Example 1
                         Find each measure.
        a. m∠YXW

                 1  1
          m∠YXW = mYW = (86) = 43°
                 2     2


                
           b. m XZ




Thursday, May 17, 2012
Example 1
                            Find each measure.
        a. m∠YXW

                 1  1
          m∠YXW = mYW = (86) = 43°
                 2     2


                
           b. m XZ
              
            m XZ = 2m∠XYZ


Thursday, May 17, 2012
Example 1
                            Find each measure.
        a. m∠YXW

                 1  1
          m∠YXW = mYW = (86) = 43°
                 2     2


                
           b. m XZ
              
            m XZ = 2m∠XYZ = 2(52)


Thursday, May 17, 2012
Example 1
                            Find each measure.
        a. m∠YXW

                 1  1
          m∠YXW = mYW = (86) = 43°
                 2     2


                
           b. m XZ
              
            m XZ = 2m∠XYZ = 2(52) =104°


Thursday, May 17, 2012
Example 2
     Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°.




Thursday, May 17, 2012
Example 2
     Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°.


                         12x −13 = 9x + 2




Thursday, May 17, 2012
Example 2
     Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°.


                         12x −13 = 9x + 2
                             3x =15




Thursday, May 17, 2012
Example 2
     Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°.


                         12x −13 = 9x + 2
                             3x =15
                              x =5




Thursday, May 17, 2012
Example 2
     Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°.


                         12x −13 = 9x + 2
                             3x =15
                              x =5


                     m∠QRT =12(5)−13




Thursday, May 17, 2012
Example 2
     Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°.


                         12x −13 = 9x + 2
                             3x =15
                              x =5


                     m∠QRT =12(5)−13 = 60 −13




Thursday, May 17, 2012
Example 2
     Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°.


                         12x −13 = 9x + 2
                             3x =15
                              x =5


                     m∠QRT =12(5)−13 = 60 −13 = 47°




Thursday, May 17, 2012
Example 3
                          Prove the following.

                 
         Given: LO ≅ MN
          Prove: MNP ≅LOP




Thursday, May 17, 2012
Example 3
                                Prove the following.

                 
         Given: LO ≅ MN
          Prove: MNP ≅LOP




          There are many ways to prove this one. Work through
           a proof on your own. We will discuss a few in class.



Thursday, May 17, 2012
Example 4
                         Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°.




Thursday, May 17, 2012
Example 4
                         Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°.
          m∠A + m∠B + m∠C =180




Thursday, May 17, 2012
Example 4
                         Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°.
          m∠A + m∠B + m∠C =180
           x + 4 + 8x − 4 + 90 =180




Thursday, May 17, 2012
Example 4
                         Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°.
          m∠A + m∠B + m∠C =180
           x + 4 + 8x − 4 + 90 =180
                 9x + 90 =180




Thursday, May 17, 2012
Example 4
                         Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°.
          m∠A + m∠B + m∠C =180
           x + 4 + 8x − 4 + 90 =180
                 9x + 90 =180
                    9x = 90




Thursday, May 17, 2012
Example 4
                         Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°.
          m∠A + m∠B + m∠C =180
           x + 4 + 8x − 4 + 90 =180
                 9x + 90 =180
                    9x = 90
                     x =10




Thursday, May 17, 2012
Example 4
                         Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°.
          m∠A + m∠B + m∠C =180
           x + 4 + 8x − 4 + 90 =180
                 9x + 90 =180
                    9x = 90
                     x =10


                 m∠B = 8(10)− 4



Thursday, May 17, 2012
Example 4
                         Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°.
          m∠A + m∠B + m∠C =180
           x + 4 + 8x − 4 + 90 =180
                 9x + 90 =180
                    9x = 90
                     x =10


                 m∠B = 8(10)− 4 = 80 − 4



Thursday, May 17, 2012
Example 4
                         Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°.
          m∠A + m∠B + m∠C =180
           x + 4 + 8x − 4 + 90 =180
                 9x + 90 =180
                    9x = 90
                     x =10


                 m∠B = 8(10)− 4 = 80 − 4 = 76°



Thursday, May 17, 2012
Check Your Understanding



                                 p. 713 #1-10




Thursday, May 17, 2012
Problem Set




Thursday, May 17, 2012
Problem Set



                         p. 713 #11-35 odd, 49, 55, 61




    “You're alive. Do something. The directive in life, the moral imperative
       was so uncomplicated. It could be expressed in single words, not
     complete sentences. It sounded like this: Look. Listen. Choose. Act.”
                                - Barbara Hall
Thursday, May 17, 2012

Geometry Section 10-4 1112

  • 1.
    Section 10-4 Inscribed Angles Thursday, May 17, 2012
  • 2.
    Essential Questions How do you find measures of inscribed angles? How do you find measures of angles on inscribed polygons? Thursday, May 17, 2012
  • 3.
    Vocabulary 1. Inscribed Angle: 2. Intercepted Arc: Thursday, May 17, 2012
  • 4.
    Vocabulary 1. Inscribed Angle: An angle made of two chords in a circle, so that the vertex is on the edge of the circle 2. Intercepted Arc: Thursday, May 17, 2012
  • 5.
    Vocabulary 1. Inscribed Angle: An angle made of two chords in a circle, so that the vertex is on the edge of the circle 2. Intercepted Arc: An arc with endpoints on the sides of an inscribed angle and in the interior of the inscribed angle Thursday, May 17, 2012
  • 6.
    Theorems 10.6 - Inscribed Angle Theorem: 10.7 - Two Inscribed Angles: 10.8 - Inscribed Angles and Diameters: Thursday, May 17, 2012
  • 7.
    Theorems 10.6 - Inscribed Angle Theorem: If an angle is inscribed in a circle, then the measure of the angle is one half the measure of the intercepted arc 10.7 - Two Inscribed Angles: 10.8 - Inscribed Angles and Diameters: Thursday, May 17, 2012
  • 8.
    Theorems 10.6 - Inscribed Angle Theorem: If an angle is inscribed in a circle, then the measure of the angle is one half the measure of the intercepted arc 10.7 - Two Inscribed Angles: If two inscribed angles of a circle intercept the same arc or congruent arcs, then the angles are congruent 10.8 - Inscribed Angles and Diameters: Thursday, May 17, 2012
  • 9.
    Theorems 10.6 - Inscribed Angle Theorem: If an angle is inscribed in a circle, then the measure of the angle is one half the measure of the intercepted arc 10.7 - Two Inscribed Angles: If two inscribed angles of a circle intercept the same arc or congruent arcs, then the angles are congruent 10.8 - Inscribed Angles and Diameters: An inscribed angle of a triangle intercepts a diameter or semicircle IFF the angle is a right angle Thursday, May 17, 2012
  • 10.
    Example 1 Find each measure. a. m∠YXW  b. m XZ Thursday, May 17, 2012
  • 11.
    Example 1 Find each measure. a. m∠YXW 1  m∠YXW = mYW 2  b. m XZ Thursday, May 17, 2012
  • 12.
    Example 1 Find each measure. a. m∠YXW 1  1 m∠YXW = mYW = (86) 2 2  b. m XZ Thursday, May 17, 2012
  • 13.
    Example 1 Find each measure. a. m∠YXW 1  1 m∠YXW = mYW = (86) = 43° 2 2  b. m XZ Thursday, May 17, 2012
  • 14.
    Example 1 Find each measure. a. m∠YXW 1  1 m∠YXW = mYW = (86) = 43° 2 2  b. m XZ  m XZ = 2m∠XYZ Thursday, May 17, 2012
  • 15.
    Example 1 Find each measure. a. m∠YXW 1  1 m∠YXW = mYW = (86) = 43° 2 2  b. m XZ  m XZ = 2m∠XYZ = 2(52) Thursday, May 17, 2012
  • 16.
    Example 1 Find each measure. a. m∠YXW 1  1 m∠YXW = mYW = (86) = 43° 2 2  b. m XZ  m XZ = 2m∠XYZ = 2(52) =104° Thursday, May 17, 2012
  • 17.
    Example 2 Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°. Thursday, May 17, 2012
  • 18.
    Example 2 Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°. 12x −13 = 9x + 2 Thursday, May 17, 2012
  • 19.
    Example 2 Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°. 12x −13 = 9x + 2 3x =15 Thursday, May 17, 2012
  • 20.
    Example 2 Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°. 12x −13 = 9x + 2 3x =15 x =5 Thursday, May 17, 2012
  • 21.
    Example 2 Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°. 12x −13 = 9x + 2 3x =15 x =5 m∠QRT =12(5)−13 Thursday, May 17, 2012
  • 22.
    Example 2 Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°. 12x −13 = 9x + 2 3x =15 x =5 m∠QRT =12(5)−13 = 60 −13 Thursday, May 17, 2012
  • 23.
    Example 2 Find m∠QRT when m∠QRT = (12x − 13)° and m∠QST = (9x + 2)°. 12x −13 = 9x + 2 3x =15 x =5 m∠QRT =12(5)−13 = 60 −13 = 47° Thursday, May 17, 2012
  • 24.
    Example 3 Prove the following.   Given: LO ≅ MN Prove: MNP ≅LOP Thursday, May 17, 2012
  • 25.
    Example 3 Prove the following.   Given: LO ≅ MN Prove: MNP ≅LOP There are many ways to prove this one. Work through a proof on your own. We will discuss a few in class. Thursday, May 17, 2012
  • 26.
    Example 4 Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°. Thursday, May 17, 2012
  • 27.
    Example 4 Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°. m∠A + m∠B + m∠C =180 Thursday, May 17, 2012
  • 28.
    Example 4 Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°. m∠A + m∠B + m∠C =180 x + 4 + 8x − 4 + 90 =180 Thursday, May 17, 2012
  • 29.
    Example 4 Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°. m∠A + m∠B + m∠C =180 x + 4 + 8x − 4 + 90 =180 9x + 90 =180 Thursday, May 17, 2012
  • 30.
    Example 4 Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°. m∠A + m∠B + m∠C =180 x + 4 + 8x − 4 + 90 =180 9x + 90 =180 9x = 90 Thursday, May 17, 2012
  • 31.
    Example 4 Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°. m∠A + m∠B + m∠C =180 x + 4 + 8x − 4 + 90 =180 9x + 90 =180 9x = 90 x =10 Thursday, May 17, 2012
  • 32.
    Example 4 Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°. m∠A + m∠B + m∠C =180 x + 4 + 8x − 4 + 90 =180 9x + 90 =180 9x = 90 x =10 m∠B = 8(10)− 4 Thursday, May 17, 2012
  • 33.
    Example 4 Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°. m∠A + m∠B + m∠C =180 x + 4 + 8x − 4 + 90 =180 9x + 90 =180 9x = 90 x =10 m∠B = 8(10)− 4 = 80 − 4 Thursday, May 17, 2012
  • 34.
    Example 4 Find m∠B when m∠A = (x + 4)° and m∠B = (8x - 4)°. m∠A + m∠B + m∠C =180 x + 4 + 8x − 4 + 90 =180 9x + 90 =180 9x = 90 x =10 m∠B = 8(10)− 4 = 80 − 4 = 76° Thursday, May 17, 2012
  • 35.
    Check Your Understanding p. 713 #1-10 Thursday, May 17, 2012
  • 36.
  • 37.
    Problem Set p. 713 #11-35 odd, 49, 55, 61 “You're alive. Do something. The directive in life, the moral imperative was so uncomplicated. It could be expressed in single words, not complete sentences. It sounded like this: Look. Listen. Choose. Act.” - Barbara Hall Thursday, May 17, 2012