已知:在\(⊙O\)中,弦\(AB⊥CD\)于点\(E\),连接\(AC\)、\(BD\),过圆心\(O\)作\(OH⊥AC\)于点\(H\).
\((1)\)如图\(1\),连接\(BC\)、\(BO\),求证:\(∠OBC+∠CDB=90^{\circ}\);
\((2)\)如图\(2\),求证:\(BD=2OH\);
\((3)\)如图\(3\),在\((2)\)的条件下,\(∠CBD=60^{\circ}\),作射线\(DO\)交\(BC\)于点\(G\),在\(CD\)上取一点\(P\)使\(ED=EP\),连接\(PB\)交\(OG\)于点\(F\),若\(PF=6\),\(\tan ∠BGD=4 \sqrt {3}\),求线段\(OH\)的长.