
20.解:(1)如图,连接OE,
∵半⊙O与AD相切于点E,
∴OE⊥AD.
∠D=90°,∴CD⊥AD,∴OE∥CD,∴.∠ECD=∠OEC.
OE=OC,∴∠OEC=∠OCE,∴∠BCE=∠DCE;
作者:网络 来源: 2022-06-09 11:29:26 阅读:次
20.解:(1)如图,连接OE, ∵半⊙O与AD相切于点E, ∴OE⊥AD. ∠D=90°,∴CD⊥AD,∴OE∥CD,∴.∠ECD=∠OEC. OE=OC,∴∠OEC=∠OCE,∴∠BCE=∠DCE;
20.解:(1)如图,连接OE,
∵半⊙O与AD相切于点E,
∴OE⊥AD.
∠D=90°,∴CD⊥AD,∴OE∥CD,∴.∠ECD=∠OEC.
OE=OC,∴∠OEC=∠OCE,∴∠BCE=∠DCE;