bonsoir
1. AM = a
a. [0 ; 3 ]
b . aire ADM = 4 a /2 = 2 a
2. AM = b
AM = 3 - b
b est compris entre 0 et 3
aire BCDM
aire ABCD = 3 * 4 = 12
aire AMD = 4 b / 2 = 2 b
aire restante = 12 - 2 b
12 - 2 b = 8
- 2 b = 8 - 12
- 2 b = - 4
b = 2
