Bonjour.
Aire triangle rectangle = (a x b)/2 = (4,8 x 6,4)/2 = 30,72/2 = 15,36 cm²
Aire demi-disque 1 = 1/2 x π x r² = 1/2 π x (4,8/2)² = 72/25 π cm²
Aire demi-disque 2 = 1/2 x π x r² = 1/2 π x (8/2)² = 8 π cm²
Aire demi-disque 3 = 1/2 x π x r² = 1/2 π x (6,4/2)² = 128/25 π cm²
Aire totale = Aire triangle rectangle + Aire demi-disque 1 + Aire demi-disque 2 + Aire demi-disque 3 = 15,36 + 72/25 π + 8 π + 128/25 π = 65,6 cm²
Bonne journée :)