Total: (15+25+25) * 32/2 =1040.

2. 1040+608= 1648 solution: 2× 2-3.14×1= 0.86 (square centimeter).

3. The blank area is 2* 10=20.

The total shadow area is 20* 10-20= 180.

s 1 = 180 * 1/5 = 36

S2= 180*4/5= 144

4. Text: 4*3*2=24 sides: (12+6+8)*2=52.

5、3. 14*( 12.56/(3. 14*2))^2*3

= 37.68 m3+04 *( 12.56/(3. 14 * 2))2+ 12.56 * 3

= 12.56+37.68

=50.24 m2, so cement 50.24 * 8 = 40 1.92kg is needed.

6, 2 * 2 * 3.14 * 0.3 *1/3 =1.256 cubic meters

I'm in trouble. I hope I can help you.

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