Answer:
1. 39 dm²
Solution:
A = LW – LW
A = (10 dm × 6dm) – (7dm × 3dm)
A = 60 dm² – 21 dm²
A = 39 dm²
2. 90 m²
Solution:
A =
[tex] \frac{a + b}{2}h + s {}^{2} [/tex]
A =
[tex] \frac{12m + 6m}{2} (6m) +( 6m) {}^{2} [/tex]
A = 9m(6m) + 36m²
A = 54 m² + 36m²
A = 90 m²
3. 100.26 cm²
Solution:
A =
[tex]lw + \ \frac{\pi \: r {}^{2} }{2} + \frac{\pi \: r {}^{2} }{2} [/tex]
A = (12cm × 6cm) + 3.14(3 cm)²/2 + 3.14(3 cm)²/2
A = 72 cm² + 14.13 cm² +14.13 cm²
A = 100.26 cm²
4. 49.04 m²
Solution:
A =
[tex]\pi \: r {}^{2} - s {}^{2} [/tex]
A = 3 14(6m)² – (8m)²
A = 3.14(36 m²) – 64 m²
A = 113.04 m² – 64 m²
A = 49.04 m²
5. 72 m²
Solution:
A = LW – 1/2bh
A = (13 m × 8m) – 1/2(8m × 8m)
A = 104 m² – 1/2(64 m²)
A = 104 m² – 32 m²
A = 72 m²
