Page 25 - Hybrid PBD 2022 Tg 5 - Matematik Tambahan
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Matematik Tambahan   Tingkatan 5  Bab 1  Sukatan Membulat

                    (c)               11.7 cm       (d)                              (e)  Diberi AB ialah diameter.
                                                                     13.1 cm  2 θ       Given that AB is a diameter.
                                       θ
                                                                    O
                                      O
                                                                                            A        2 θ  B
                            8.9 cm
                                                                                                   O
                                                                  26.8 cm
                       2πj = 11.7 + 2(8.9)                         26.8
                                                                                             π
                          j = 4.695 cm                    2π – 2q  =   13.1             2q =   × 3
                         q =   11.7                 	   	     q	= 2.12 rad                   5
                             4.695                                                      q =  3π  rad
                    	  	  	= 2.492 rad                                                      10
                                                                                          = 0.942 rad
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                6.  Tentukan perimeter tembereng yang berlorek bagi setiap bulatan berpusat O yang berikut.   SP 1.2.2     TP4
                  Determine the perimeter of the shaded segment of each of the following circles with centre O.

                                                                     (a)
                       P                                                                P          Q
                                        Tip Penting                                         1.3 rad
                                    Perentas PQ dapat diperolehi dengan                        7.5 cm
                                    petua kosinus, iaitu                                     O
                          0.4π rad  PQ = √
                                          j  + j  – 2j  kos q, dengan q
                                          2
                                             2
                                                2
                         9.6 cm     dalam darjah.
                       Q            The chord PQ can be obtained by using the   1.3 rad = 1.3 ×  180°  = 74.48°
                                    cosine rule, that is                               π
                                    PQ = √
                                         j  + j  – 2j  cos q, such that q is in
                                         2
                                            2
                                               2
                                                                                    7.5  + 7.5  – 2(7.5)  kos 74.48°
                                                                                       2
                                                                                                     2
                                                                                             2
                                    degrees.                            Maka, PQ = √
                                    180°                                Hence    = 9.08 cm
                    0.4p rad = 0.4p ×    = 72°
                                     π                                  Panjang lengkok PQ = jq = 7.5(1.3)
                    Maka, PQ = √                                       Arc length of PQ
                                         2
                                                2
                                   2
                                9.6  + 9.6  – 2(9.6)  kos 72°
                    Hence    = 11.29 cm                                                        = 9.75 cm
                    Panjang lengkok PQ  = jq = 9.6(0.4π)                Perimeter tembereng berlorek  = 9.08 + 9.75
                    Arc length of PQ   = 12.06 cm                       Perimeter of the shaded segment   = 18.83 cm
                    Perimeter tembereng berlorek  = 12.06 + 11.29
                    Perimeter of the shaded segment   = 23.35 cm
                                                                     (c)                     P
                    (b)                         P
                                                                                        2.8 cm
                                          7.2 cm
                                                                                          O       5.25 cm
                                              O
                                           4.2 rad
                                                  Q
                                                                                              Q
                       Panjang lengkok minor PQ                         Panjang lengkok major PQ
                       Minor arc length of PQ                                           Major arc length of PQ
                       = (2π – 4.2) × 7.2                               = 2π(2.8) – 5.25 = 12.34 cm.
                       = 15 cm                                          ∠POQ =   5.25
                       /POQ = 2π – 4.2 = 2.08 rad                                 2.8
                                       = 119.36°                               = 1.875 rad 180
                                   7.2  + 7.2  – 2(7.2)  kos 119.36°
                       Maka, PQ = √                                          = 1.875 ×   p
                                            2
                                                   2
                                      2
                       Hence    = 12.43 cm                                     = 107.43°
                                                                                    2.8  + 2.8  – 2(2.8)  kos 107.43°
                                                                                             2
                                                                                                     2
                                                                                       2
                       Perimeter tembereng berlorek  = 15 + 12.43       Maka, PQ = √
                       Perimeter of the shaded segment   = 27.43 cm     Hence    = 4.51 cm
                                                                        Perimeter tembereng berlorek  = 12.34 + 4.51
                                                                        Perimeter of the shaded segment   = 16.85 cm
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