Page 10 - PBD Plus Matematik Tambahan T5 (EG)

Matematik Tambahan Tingkatan 5 Bab 1 Sukatan Membulat

4. Tentukan jejari bulatan, j, diberikan panjang lengkok dan sudut bagi setiap bulatan yang berikut.
Determine the radius of the circle, j, given the arc length and the angle in each of the circles. TP 2
Contoh
(a) (b)
14.5 cm j 46.8°

4.68 rad O j
O j 4 _ θ O
23.6 cm 3 π rad
56.8 cm
23.6 q = 360° – 46.8°
j = 4
s = jq 3 π = 313.2°
j = s = 5.634 cm q° = s
q 360° 2πj
j = 14.5 313.2° = 56.8
4.68 360° 2πj
= 3.1 cm 56.8 × 360°
j =
313.2° × 2π
= 10.39 cm

(d) (e)
(c)
6.3 cm π __ 21.4 cm
j
8
j
1.41 rad θ O O j
31.2 cm
O

3
π
s = jq q = 2π – π + 2  24 = 5π q° = s
4
8
j = s Penerbitan Pelangi Sdn. Bhd. 360° 2πj

q 31.2 120° = 21.4
j = 6.3 j = 5π 360° 2πj
1.41 4 21.4 × 360°
= 4.47 cm = 7.95 cm j = 120° × 2π
= 10.22 cm

5. Tentukan sudut tercangkum, q dalam radian, di pusat bulatan dengan diberikan jejari bulatan dan panjang
lengkok bagi setiap bulatan yang berikut. TP 3
Determine the subtended angle, q, in radians, at the centre of the circle given that the radius and the arc length of each of the following
circles.

Contoh
(a) (b)
4.8 cm 33.7 cm

θ θ O 5.8 cm
1.3 cm O O 13.4 cm θ

4.4 cm
Daripada/From s = jq 4.4

q = s q = 33.7 2π – 3q = 5.8
j 13.4 q = 1.84 rad
q = 4.8 q = 2.515 rad
1.3

q = 3.692 rad

TAHAP PENGUASAAN 1 2 3 4 5 6 3 © Penerbitan Pelangi Sdn. Bhd.