a: Cac cap tam giac dong dang la:
HBA~ABC
HBA~HAC
HAC~ABC
b,Xet tam giac ABC vuong tai A:
AB^2+AC^2 =BC^2(dinh li PyTaGo)
6^2+8^2=BC^2
BC^2=100
BC=10cm
Xet tam giacHBA va ABC co
Goc B chung(gt)
GocBHA=GocBAC=90 do(gt)
Vay tam giac HBA~ABC(g-g)
=>AH/AC=BA/BC(tsdd)
=>AH/8=6/10
=>AH=(8.6)/10=4,8cm