Question

[Nguyen Thi Thu Hien]

Ban nao biet lam jup minh cau d, bai nay voi.

cho (O;R) duong kinh AB va day AC>R. Qua O ve duong thang vuong goc voi AC tai H, duong nay gap tiep tuyen tai A cua (O) o D.

a, chung minh OD la trung truc cua AC va HA.HC=HO.HD.

b, chung minh DC la tiep tuyen cua (O).

c, duong thang qua O va vuong goc AB gap BC tai F, chung minh OD song song BC va OCFD la hinh thang can. d, goi I la giao diem cua OF va DC. BI gap AD tai K. chung minh AD.DK=R^2

Answer 1

[Cao Thi Thuy Duong]

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