Ducem inaltimea CH
BH=AB-CD=18-10=8 cm
cosB=BH/BC BC=BH/cosB=8/√3/2=16/√3
sinB=CH/BC CH=BC*sinB=16/√3*1/2=8/ √3 si CH=AD
Perimetrul=P=AB+BC+CD+DA=18+16/√3+10+8/√3=28+24/√3
Aria=A=CH*(AB+CD)/2=8/√3*28/2=112/√3
La punctul c este o eroare; doua segmente nu se pot intersecta decat intr-un singur punct (in cazul nostru B=M)