Solution: analysis, cutting along the diameter means that the knife edge goes along the diameter. For example, walking along the river is not to cut off the river, but to walk along the river. Therefore, cutting along the diameter is transverse; ? Cutting along the height means that the blade goes along the height, and the height cannot be cut off, so cutting along the height is longitudinal.

Saw in half along the diameter "is transverse, and the surface area is increased by two bottom areas:

3. 14×(5÷2)? ×2

=3. 14×6.25×2

=39.25(cm？ )