将五边形纸片ABCDE按如图所示的方式折叠,折痕为AF,点E、D分别落在,已知∠AFC=76º,则等于（）图在：file:///C:/Documents%20and%20Settings/Administrator/Local%20Settings/Temporary%20Internet%20Files/Content.IE5/VYS

Question

将五边形纸片ABCDE按如图所示的方式折叠,折痕为AF,点E、D分别落在,已知∠AFC=76º,则等于（ ）
图在：file:///C:/Documents%20and%20Settings/Administrator/Local%20Settings/Temporary%20Internet%20Files/Content.IE5/VYS7GWD3/image003%5B1%5D.jpg
请大家写清解题过程!好的加分!

Answer 1

∠AFD=180°-76°=104°
∠AFD=∠AFD'
∠AFD'-∠AFC=76°
∠CFD'=104°-76°=28°
∠CFD'=28°
或者
∵折叠前后部分是全等的
又∵∠AFC+∠AFD=180°
∴∠AFD′=∠AFD=180°-∠AFC=180°-76°=104°
∴∠CFD′=∠AFD′-∠AFC=104°-76°=28°