如图,\(⊙O_{1}\)和\(⊙O_{2}\)公切线\(AD\)和\(BC\)相交于点\(D\),\(A\)、\(B\)、\(C\)为切点,直线\(DO_{1}\)与\(⊙O_{1}\)与\(E\)、\(G\)两点,直线\(DO_{2}\)交\(⊙O_{2}\)与\(F\)、\(H\)两点.
\((1)\)求证:\(\triangle DEF~\triangle DHG\);
\((2)\)若\(⊙O_{1}\)和\(⊙O_{2}\)的半径之比为\(9\):\(16\),求\( \dfrac {DE}{DF}\)的值.