^-^ giup e vs a
cho nua dg tron ban kinh AB . ke cac tiep tuyen Ax va By cung phia vs nua dg tron doi vs AB . Ve ban kinh OE bat ki . tiep tuyen cua nua dg tron tai E cat Ax ,By theo thu tu o C va D
a)Cm rang CD = AC+BD
b) Cm OC vuong goc vs OD
c) Tinh do dai ban kinh OE neu bt AC=2cm ;BD =8cm
d) Cm AB la tiep tuyen cua dg tron ngoai tiep tam giac OCD
Loga
Sinh Học lớp 12
