Page 12 - Modul A+1 Matematik Tambahan Tingkatan 5

2. Hitung jejari, j dan/atau sudut q, dalam radian, bagi setiap yang berikut.
Calculate the radius, j and/or the angle q, in radians, for each of the following. TP 3

Contoh/Example (a)
Luas kawasan berlorek
Luas kawasan berlorek Area of the shaded region
7 cm
Area of the shaded region = 20 cm 2
θ = 24 cm 2 1.3 rad BAB 1
j

1 (1.3)j = 20
2
Luas/Area = j q 2
1 2
2 j = 20 × 2
2
1
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24 = (7) q 1.3
2
2 j = 5.55 cm
q = 48
49
= 0.98 rad

(b) (c)
Luas kawasan berlorek 10 cm Luas kawasan berlorek
Area of the shaded region Area of the shaded region
O = 100 cm 2 = 30 cm 2
θ j
10 cm θ

1
j q = 30 .................a
100 = (10) (2π – q) 1 2
2
2
2 jq = 10 .................b
2 = 2π – q 1
q = 2π – 2 a ÷ b 2 j = 3
= 4.28 rad j = 6 cm
ºq = 10
6
= 5 rad
3

3. Hitung luas bagi setiap kawasan berlorek yang berikut.
Calculate the area for each of the following shaded regions. TP 4

Contoh/Example (a) P
2.3 cm
O
5 cm S 1.4 rad Q
1.6 rad D R
3 cm
A C O

B

1
Luas/Area OBC = (8) (1.6)
2
2 Luas kawasan berlorek
1
Luas/Area OAD = (5) (1.6) 1 1
2
2 = (4.6) (2π – 1.4) – (2.3) (2π – 1.4)
2
2
2
2
Luas kawasan berlorek = 38.75 cm 2
Area of the shaded region
1
1
= (8) (1.6) – (5) (1.6)
2
2
2 2
= 31.2 cm 2
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01 Modul Series MateTam Tg5.indd 9 04/10/2021 2:15 PM