Bonjour,
Figure 1:
Aire rectangle: 12x8= 96 m²
Aire triangle: (8x6)/2= 24 m²
Aire figure: 96+24= 2 304 m².
Figure 2: une des méthodes
Aire grise: (10x4)= 40 cm²
Aire blanche: 1x7= 7 cm²
Aire figure: 40-7= 33 cm²
Figure 3:
Aire carré: 3x3= 9cm²
Aire triangle: (3x4)/2= 6 cm²
Aire figure: 9+6= 15 cm².
Figure 4:
rayon de ce cercle: 10/2= 5 cm
Aire cercle: 5² x 3.14= 25 x 3.14= 78.5 cm²
