grazie scusate per l’orario
perimetro 2p = x(5+9+13+21)/4 = 12 u
area A = 15x/4*5x/4 = 75x^2/16 u^2
per x = 2
2p = 12*2 = 24 u
A = 75/4 U^2
per x = 4
2p' = 12*4 = 48 u
A' = 75*16/16 = 75 u^2
per x = 3/2
2p'' = 12*3/2 = 18 u
A'' = 75*9/(16*4) = 10,55 u^2