Page 16 - PBD Plus Matematik Tambahan T5 (EG)
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Matematik Tambahan   Tingkatan 5  Bab 1  Sukatan Membulat

                   (b)   Diberi POQ dan SOR             P           (c)
                      adalah dua sektor dengan                T                          P
                      pusat O dan /POQ = 2SOR         3 cm
                      = 1.3 rad. Cari jumlah luas         O     Q                    O         A
                      rantau berlorek.             S
                      Given that POQ and SOR are two   U                                Q
                      sectors with centre O and /POQ =   R             Diberi /PAQ = 45° dan PA = 6 cm dan OP = 5 cm.
                      2SOR = 1.3 rad. Find the total area
                      of shaded region.                                Cari luas rantau berlorek.
                                                                       Given /PAQ = 45° and PA = 6 cm and OP = 5 cm. Find the area
                                              1
                      Luas sektor POQ =   j q =   (3) (1.3)            of shaded region.
                                                   2
                                        1 2
                      Area of sector POQ  2   2
                                      = 5.85 cm 2                      Perentas PQ = √
                                                                                      6  + 6  – 2(6)  kos 45°
                                                                                                  2
                                                                                           2
                                                                                       2
                      1.3 rad =  1.3   × 360° = 74.48°                 Chord PQ    = 4.59 cm
                                2π                                                      2   2     2
                                          1
                      Luas segi tiga POQ =  (3) sin 74.48°             kos/cos /POQ =   5  + 5  – 4.59
                                              2
                                                                                              2
                                                                                           2(5)
                      Area of triangle POQ  2
                                       = 4.34 cm 2                             /POQ = 54.65°
                                                                                     = 0.954 rad
                      Maka, luas tembereng PTQ  = 5.85 – 4.34
                     Hence, area of segment PTQ   = 1.51cm 2           Luas rantau berlorek
                                                                       Area of shaded region
                                             1
                                                   2
                      Luas sektor SOR =   j q =  ( 3) 2 1.3               1  2         1  2         1  2
                                       1 2
                                                                                       2
                                                                                                    2
                      Area of sector SOR  2  2      2                  =  2 (6) (0.785) –  (6 )sin 45° +  (5 )(0.954)
                                       = 2.93 cm 2                       –  ( 5) sin 54.65°
                                                                           1
                                                                               2
                       1.3  rad =  0.65  × 360° = 37.24°                   2
                        2       2p                        2Pelangi Sdn. Bhd.
                                                                       = 3.13 cm
                                                                                2

                                         1
                      Luas segi tiga SOR =  (3) sin 37.24°
                                             2
                      Area of triangle SOR  2
                                       = 2.72 cm 2
                      Maka, luas tembereng SUR = 2.93 – 2.72
                      Hence, area of segment SUR    = 0.21cm 2
                                    Penerbitan
                       Jumlah luas rantau berlorek  = 1.51 + 0.21
                      Total area of the shaded region   = 1.72 cm
























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