As shown in the figure, fold the rectangular piece of paper ABCD so that point a coincides with point C, the crease is EF, and ∠ BFC = 65 °, then ∠ bec=

∵∠EFC=65°
The two straight lines are parallel and the internal stagger angle is equal
And ∵ ∠ FEC = ∠ FEA (known by folding)
∵∠ FEA + ∠ FEC + ∠ BEC = 180 ° (definition of horizontal angle)
∴∠BEC=180°-∠FEA-∠FEC=180°-2∠EFC=180°-130°=50°

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