a =12 cm si b = 8 cm
Aria = a × b = 12 × 8 = 96 cm²
a)
a'= a+3 = 12+3 = 15
b' = b - 3 = 8 - 3 = 5
Aria A' = a' × b' = 15 × 5 = 75 cm²
aria scade de la 96 cm² la 75 cm² , deci de 1,28 ori
b)
a''= a×(2/3)=(12×2):3= 8 cm
b'' = b ×(1/4) = (8 ×1 ):4 = 2 cm
Aria A'' =a'' × b''= 8 × 2 = 16 cm²
aria scade de la 96 cm² la 16 cm² deci scade de 6 ori
