共50条信息
如图,\(\triangle ABC\)是\(⊙O\)的内接三角形,点\(C\)是优弧\(AB\)上一点\((\)点\(C\)不与\(A\),\(B\)重合\()\),设\(∠OAB=α\),\(∠C=β\).
\((1)\)当\(α=35^{\circ}\)时,求\(β\)的度数;
\((2)\)猜想\(α\)与\(β\)之间的关系,并给予证明.
如图,\(AD\)是\(⊙O\)的直径,\(AB\)为\(⊙O\) 的弦,\(BC\)与\(⊙O\)相切,\(B\)为切点,\(OP\)与\(AB\)的延长线交于点\(P.\)点\(C\)在\(OP\)上,且\(BC=PC\).
\((1)\)求证:\(OP⊥AD\);
\((2)\)若\(OA=3\),\(AB=2\),求\(BP\)的长.
如图\(①\),在\(\triangle ABC\)中,点\(D\)在边\(BC\)上,\(∠ABC:∠ACB:∠ADB=1:2:3\),\(⊙O\)是\(\triangle ABD\)的外接圆.
\((1)\)求证:\(AC\)是\(⊙O\)的切线;
\((2)\)当\(BD\)是\(⊙O\)的直径时\((\)如图\(②)\),求\(∠CAD\)的度数.
如图\(①\),在\(\triangle ABC\)中,点\(D\)在边\(BC\)上,\(∠ABC︰∠ACB︰∠ADB=1︰2︰3\),\(⊙O\)是\(\triangle ABD\)的外接圆.
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