S1=ah=3
S2=(a+0.5a)h/2=1.5ah/2=0.75ah
S2=0.75*3=2.25
ответ: 2.25
S(AHCB)=S(ABCD)-S(HCD)=AD*H(AD)-1/2HD*H(AD)=3-1/4AD*H(AD)=3-3/4=9/4
S1=ah=3
S2=(a+0.5a)h/2=1.5ah/2=0.75ah
S2=0.75*3=2.25
ответ: 2.25
S(AHCB)=S(ABCD)-S(HCD)=AD*H(AD)-1/2HD*H(AD)=3-1/4AD*H(AD)=3-3/4=9/4