2001阅读题

ab =交流∴∠B=∠C

3、∫ad = AE ∴∠ade=∠aed

∠∠ADC =∠b+∠BAD =∠ADE+∠EDC

∠AED=∠C+∠EDC

∴∠B+∠BAD=∠C+2∠EDC

∴∠EDC=1/2∠BAD

1,∠EDC = 10

2、∠BAD=40