如图在圆O中,AB,CD是两弦,且AB>CD,OE⊥AB于点E,OF⊥CD于点F.求证OE
问题描述:
如图在圆O中,AB,CD是两弦,且AB>CD,OE⊥AB于点E,OF⊥CD于点F.求证OE
答
证明:∵OE⊥AB∴AE=AB/2∴OE²=OA²-AE²∵OF⊥CD∴CF=CD/2∴OF²=OC²-CF²∴OE²-OF²=OA²-AE²-OC²+CF²=CF²-AE²=(CD/2)²-(AB/2)...