cho 4 duong thang xx’,yy’,zz’,mm’ cung di qua diem o a) viet ten cap tia b) co tat ca bn cap tia ko doi nhau
By Hailey
cho 4 duong thang xx’,yy’,zz’,mm’ cung di qua diem o a) viet ten cap tia b) co tat ca bn cap tia ko doi nhau
A )tia ox , ox’ ,oy ,oy’ ,om ,om’
B)có tất cả 3 cặp tia đối nhau