Răspuns:
Explicație pas cu pas:
a) c₁ = 30 cm ; c₂ = 40 cm =>
A = c₁·c₂/2 = 30·40:2 = 30·20 = 600 cm²
b) b = 16 mm ; h = 10 mm =>
A = b·h:2 = 16mm · 10 mm :2 = 16·5 = 80 mm²
c) c₁ = c₂ = 8 m =>
A = 8 m ·8 m :2 = 8·4 = 32 m²
d) ip = 6 cm ; c₁² + c₂² = ip² ; c₁ = c₂ = c =>
2c² = ip² => c² = ip²:2 = 6²:2 = 36:2 = 18 cm²
A = c²:2 = 18 cm² :2 = 9 cm²