9.
\((1)①-{a}^{2}{b}^{3}=3 \)求\(-{a}^{6}{b}^{9}=3 \) \(=\)____
\(②{{(-{{y}^{4}})}^{2}}=\)___________
\(③{\left(- \dfrac{7}{12}\right)}^{2008}×{\left( \dfrac{12}{7}\right)}^{2008} \)_________
\((2)\)如图,在\(\triangle ABC\)中,\(∠C=90^{\circ}AD\)平分\(∠BAC\),\(BC=10cm\),\(BD=6cm\),则点\(D\)到\(AB\)的距离为\(__\).
\((3)\)若点\(A(m+2,3)\)与点\(B(-4,n+5)\)关于\(x\)轴对称,则\(m+n=\)_________ .
\((4)\)若等腰三角形一腰上的高与另一腰的夹角的度数为\(30^{\circ}\),则它的顶角为__________ .
\((5)\) 如图,\(AD\)为\(\triangle ABC\)的中线,\(BE\)为三角形\(ABD\)中线,
\(①∠ABE=15^{\circ}\),\(∠BAD=35^{\circ}\),求\(∠BED\)的度数_______
\(②\)若\(\triangle ABC\)的面积为\(60\),\(BD=5\),则点\(E\)到\(BC\)边的距离为_______
\((6)\)已知一个多边形的内角和和外角和的差是 \(1080^{0\;}\),则这个多边形_______边形,从一个顶点出发可以引________条对角线。
\((7)\)如图,在\(\triangle ABC\)中,已知\(AB=AC\),\(∠BAC\)和\(∠ACB\)的平分线相交于点\(D\),\(∠ADC=125^{\circ}.\)求\(∠ACB=\)_______度,\(∠BAC=\)_______度.
\((8)\)如图,\(\triangle ABC\)中,\(AB=AC\),\(∠BAC=54^{\circ}\),点\(D\)为\(AB\)中点,且\(OD⊥AB\),\(∠BAC\)的平分线与\(AB\)的垂直平分线交于点\(O\),将\(∠C\)沿\(EF(E\)在\(BC\)上,\(F\)在\(AC\)上\()\)折叠,点\(C\)与点\(O\)恰好重合,则\(∠OEC\)为________度.