The students of the model airplane group want to cut a trapezoid from the rectangular material AECFk, as shown in the shadow, to make the wing. Please calculate seven e and CD according to the data in

The students of the model airplane group want to cut a trapezoid from the rectangular material AECFk, as shown in the shadow, to make the wing. Please calculate seven e and CD according to the data in figure K. ∫≈E port C = 18p- 1SP = 6p,

∴, port E= 1cc≈sc in RT delta port CE,

∵ In Rt△ADF ∠ mouth AF= big mouth,

∴AF=FD= 1，

∴CD=s8+sc- Da 1= 1p，

∴S trapezoidal port a CD =1s (1p+S8) × da1= 77 ta (cm) s.