Bonjour pourriez vous m’aider à un exercice sur le théorème de Thales svp

AE/AB = AF/AC=EF/BC
X/5=AF/8
AF=(X/5)*8=8x/5

P(EFCB)= EF + BC + EB + CF
= > EF = AF/AC * BC = (8x/5)/8 * 6 = 6x/5

P(EFCB)= 6x/5 + 8 + EB + CF

EB = AB - AE = 5 - x
CF = AC -AF = 8 - 8x/5

P(EFCB)=6x/5+8+(5-x)+(8-8x/5)

P(EFCB)=-2x/5+21-5x/5= 21-7x/5