S=r^2ПИ
ПИ=3,14
а)S=0,4^2 × 3,14=0,5024 м
б)S=0,01^2 × 3,14=0,000314 дм
в)S=1/2^2 × 3,14=0,785
г)S=14/5^2 × 3,14=24,6176 см
S=r^2ПИ
ПИ=3,14
а)S=0,4^2 × 3,14=0,5024 м
б)S=0,01^2 × 3,14=0,000314 дм
в)S=1/2^2 × 3,14=0,785
г)S=14/5^2 × 3,14=24,6176 см