Répondre :
figure 1
aire=π*1,4²-π*0,4²
=1,8π
=5,65 cm²
figure 2
aire=2*(1*2)+2*(π*1²/2)+4*(1*1/2)
=4+π+2
=9,14 cm²
figure 3
aire=3*2+2*(3/4*π*1²)
=6+3/2π
=7,71 cm²
figure 4
aire=3*3/2-1/2*(π*1²)
=9/2-π/2
=2,93 cm²
figure 1
aire=π*1,4²-π*0,4²
=1,8π
=5,65 cm²
figure 2
aire=2*(1*2)+2*(π*1²/2)+4*(1*1/2)
=4+π+2
=9,14 cm²
figure 3
aire=3*2+2*(3/4*π*1²)
=6+3/2π
=7,71 cm²
figure 4
aire=3*3/2-1/2*(π*1²)
=9/2-π/2
=2,93 cm²