1 hcn cocd gap 3/2 cr keo dai cd them 1/6 cd va keo dai cr them 1/4 cr thi duoc 1 hcn co s moi hon s cu la 132m tinh s hcn ban dau
tinh s hcn biet rang cd tang 20% cr giam 20% thi s bi giam 30 m2
1 hcn gap 2 lan CR . Neu tang CD them 10m va tang CR them 15mthi duoc hcn co CD gap ruoi CR
a)tinh CD,CR hcn ban dau
b) tinh chu vi , dien tich hcn ban dau
giup mk di mk dang can gap mai phai nop bai roi!
Cho HCN biet neu tang dai 20 % va giam rong 20 % thi S giam 150 m vuong . tinh S ban dau
neu giam CD hcn 20% thi CR hinh do tang them bn % de S ko thay doi
tim dien tich chu nhat neu cd tang 20 0/0 va cr giam 20 0/0 thi s bi giam 30m2
Mot hcn co cd gap ruoi cr .neu moi chieu tang them 2m thi hcn moi co dien tich tang them 64m2.tinh dt ban dau hcn
1 manh vuon hcn co chieu dai = 2 lan chieu rong . neu cr tang 2 m va giam cd 2 m thi dt manh vuon tang 12 m2 . tinh dt manh vuon
Mieng bia hcn co chu vi gap 5 lan CR . Neu tang CR them 9 cm , tang CD them 4 cm thi duoc mot hinh vuong . Tim DT mieng bia ban dau