Question 1, look at the question and understand the meaning of the question. There are three different ways to expand the side of a cylinder, so there are three kinds of expansion diagrams. Figure 1: The profile is a rectangle, and the width is the height of the cylinder. Don't draw it again. Figure 2: Tear the side at will and draw a vertical line between parallel lines. Figure 3: The side spread is a parallelogram with vertical lines drawn between the bottom sides.

Question 2. Underline the words: circumference, height and bottom circle of cylindrical lampshade. Mark "Side" on "Lampshade". Formula calculation, 47.1× 35× 20 = 47.1× 70 = 3297 (cm2).

Question 3, "Volume" is underlined to indicate the volume formula of various graphs. Then use the formula to calculate. ( 1)8.5×4×3 = 102(dm3)； (2)π×(8/2)2×5 = 80π(cm3)； (3) 1/3×π×( 15/2)×( 15/2)×8 =π×5× 15×2 = 150π(cm3)。

Question 4: This is honeycomb coal with holes 12, and the volume of holes 12+the volume of coal = the volume of big cylinder. In the formula calculation, π× (12/2) 2 = 36π (cm3), π× (2/2) 2 = π (cm3), 36π- 12π = 24π ≈ 75 (cm3).

Question 5: The volume of a cone is converted into the volume of a cuboid. Cone sand pile, bottom area and height. Imagine laying this pile of sand on the road and turning it into a cuboid: width 10m, height 2cm, and unknown length. Mark "0.02m" on "2cm". Calculation of column equation.

Solution: suppose you can lay x meters.

10×0.02×x = 1/3×28.26×2.5

0.2x=9.42×2.5

x= 1 17.75

Question 6: When the sum of the diameters of the cylinder is higher than the side length of the cube, the volume of the cylinder is the largest. The volume of the cylinder is 3.14× 22× 4 = 3.14× 4× 4 = 50.24 (dm3).