Cho tam giac ABC vuong tai A , duong cao AH , phan giac AD
a, CM AB^2 = BH . HC
b, cho BC =25 , BH=9 . Tinh chu vi tam giac ABC va dien tich tam giac ABC
c, Tinh AD dua tren yeu cau cua cau b .
hinh ko can ve , phan a minh cm dc roi . Cac ban giup minh phan b ,c nhe ! Lam on .