1. If the long side of a diagonal rectangle is regarded as the height of a cylinder and the short side is not long enough to be rolled up, then the long side can only be rolled up.

2r+2πr=8.28 r= 1 dm

So the short side is 4, and the volume is: 4*πr*r= 12.56 dm?

2. Connect AC and pass a point O with BD, so because it is a square, O is the midpoint of BD, and AO=BO=FB= 1.5.

3、Sabcd=8*8=64

sabf = AB * BF/2 = 8 *(8+cf)/2 = 64+ 12 = 76