Page 38 - Lösung Merkheft
P. 38

2.9.  KREISBOGEN UND KREISAUSSCHNITT





                                         1          90°                                     1       90°
                                  As =  ∙ A →            ∙ πr²                         b =  ∙ u →   360°  ∙ 2πr
                                                                                            4
                                         4         360°


                                            1       180°
                                      As =  ∙ A →         ∙ πr²                             1       180°  ∙ 2πr
                                            2       360°                               b =  ∙ u →
                                                                                            2       360°


                                            3       270°
                                      As =  ∙ A →         ∙ πr²                             3       270°  ∙ 2πr
                                            4       360°                               b =  ∙ u →   360°
                                                                                            4



                                      Kreisausschnitt As                                 Kreisbogen b

                                                     2                                          
                                      As =    360°  ∙ πr                              b =    180°  ∙ πr






                   r=3 cm  α=58°        As=8,3 cm²α=60°         b=6,98 mr=2,6 m       r=12 mAs=56,5 m²
                      As=?  b=?               r=?    b=?             α=?     As=?             α=?    b=?
                                                           360                    180                      360
                                2
                                                      2
                                                                                                      2
                As =         ∙ πr       As =       ∙ πr     | ∙    b =     ∙ πr  | ∙    As =       ∙ πr     | ∙
                       360°                   360°           ∙        180°           ∙        360°           ∙   

                        58°                         ∙ 360                ∙ 180                     ∙ 360
                                          2
                                2
                As =         ∙ π3       r =             |ඥ          =                       =
                       360°                         ∙ π                    ∙ π                    ² ∙ π
                                               8,3 ∙ 360
                As =   4,56     ²       r = √    60 ∙ π               6,98 ∙ 180              56,5 ∙ 360
                                        r =   4,0                   =    2,6 ∙ π            =    12 ∙ π
                                                                                                   2
                          
                b =        ∙ πr
                      180°                                          =   153,82°          α =   45°
                                        b =        ∙ πr
                       58°                    180°                                                
                b =        ∙ π ∙ 3                                                       b =        ∙ πr
                      180°                     60°                                            180°
                                        b =        ∙ π ∙ 4       As =   360° ∙ πr²
                b =   3,04                    180°                                             45°
                                                                                         b =        ∙ π ∙ 12
                                        b =   4,19               As =  153,82° ∙ π ∙ 2,6²     180°
                                                                       360°
                                                                                         b =   9,42   
                                                                 As =   9,07     ²




                                                            38
   33   34   35   36   37   38   39   40   41   42   43