Page 71 - Steady Mate Tg1 - Book B

Matematik Tingkatan 1 Bab 10 Perimeter dan Luas

2
2
Contoh 7. Luas / Area = 30 cm 8. Luas / Area = 144 cm
Luas / Area = 70 cm 2
x cm
x cm x cm 12 cm
24 cm

14 cm
1 × 2x × 12 = 30 1 × 2x × 24 = 144
1 2 2
× 2x × 14 = 70 12x = 30 24x = 144
2
14x = 70 x = 2.5 x = 6
x = 5

2
2
Contoh 9. Luas / Area = 40 cm 10. Luas / Area = 48 cm
Luas / Area = 28 cm 2 8 cm 4 cm
6 cm
x cm x cm
x cm
12 cm 12 cm
8 cm
1 1
× (8 + 12) × x = 40 × (4 + 12) × x = 48
1 2 2
× (6 + 8) × x = 28
2 10x = 40 8x = 48
7x = 28
x = 4 x = 6
x = 4

2
Contoh 11. Luas / Area = 175 cm 12. Luas / Area = 57 cm
2
Luas / Area = 80 cm 2
9 cm
8 cm
10 cm
x cm
8 cm
x cm
4 cm
x cm 1 6 cm
× (9 + x) × 10 = 175
1 2 1 × (4 + x) × 6 = 57
× (8 + x) × 8 = 80 2
2 (9 + x) × 5 = 175
(8 + x) × 4 = 80 (4 + x) × 3 = 57
9 + x = 35
8 + x = 20 4 + x = 19
x = 26
x = 12 x = 15

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