D
ducdun


cho tam giac ABC can tai A co A bang 20 do
cac diem M,N theo thu tu thuoc cac canh ben AB , AC sao cho goc BCM =50 do, CBN bang 60 do.
tinh MNA.@-)
cac diem M,N theo thu tu thuoc cac canh ben AB , AC sao cho goc BCM =50 do, CBN bang 60 do.
tinh MNA.@-)