9.
如图,\(AB\),\(BC\)分别是\(⊙O\)的直径和弦,点\(D\)为\(BC\)弧上一点,弦\(DE\)交\(⊙O\)点\(E\),交\(AB\)于点\(F\),交\(BC\)于点\(G\),过点\(C\)的切线交\(ED\)的延长线于点\(H\),且\(HC=HG\),连接\(BH\),交\(⊙O\)于点\(M\),连接\(MD\),\(ME\).
\((1)\)求证:点\(B\)为弧\(DE\)的中点;
\((2)\)求证:\(∠HMD=∠MHE+∠MEH\);
\((3)\)若\(HC=3M=BG\),\(⊙O\)的半径为\(4\),\(\tan \angle ABC=\dfrac{3}{4}\),求\(HC\)和\(DG\)的长度.