1,

Bottom circumference = diameter * pi = 24 * 3.14 = 75.36cm.

Transverse area = bottom perimeter * column height = 75.36 * 8 = 602.88cm2.

Radius = diameter/2 =12cm

Bottom area = radius square * pi =12 *12 * 3.14 = 452.16cm2.

Total area =2 bottom areas+side area =1507.2cm2.

2,

Side area = bottom perimeter * column height =3. 14*5= 157 square meters.

Radius of base circle = perimeter/π /π/2 = 0.5m

Bottom area = radius square * pi =0.5*0.5*3. 14=0.785 m2.

Total area =2 floor area+side area =158.57m2.

3,

Bottom circumference = diameter *π= 2 * 2.5 * 4 = 20 decimeters

Transverse area = bottom perimeter * column height =20*4=80 square decimeter.

Bottom area = radius square * pi = 2.5 * 2.5 * 3.14 =19.625 square decimeter.

Total area =2 bottom areas+lateral area = 1 19.25 square decimeter.

4,

Bottom circumference = diameter * pi =18 * 3.14 = 56.52cm.

Cloth area = lateral area = bottom circumference * column height =56.52*80=452 1.6 cm2.

Radius = diameter /2=9 cm

Yellow cloth area =2 base area = radius square *π= 2 * 9 * 9 * 3. 14 = 508.68 square centimeters.

5,

Intermediate shaft side circumference = diameter * pi = 3.5 * 3.14 =10.99 cm.

Height of intermediate shaft = width of toilet paper = 10 cm.

Intermediate shaft area = perimeter * height =10 *10.99 =109.9cm2.

6,

Bottom circumference = diameter * pi = 20 * 3.14 = 62.8cm2.

Side area = bottom perimeter * height =30*62.8= 1884 cm2.

Bottom radius = diameter/2 =10cm

Bottom area = radius square * pi = 3 14cm2

Total area =2 bottom surfaces+side surface area = 2512cm2.

Color paper area = total area-hollowed-out area of upper and lower bottom surfaces =25 12-78.5-78.5=2355 square centimeters.

7,

Bottom diameter = height *3/4=9 decimeters

Bottom radius = diameter /2=4.5 decimeter.

Area of the bottom of the barrel = radius square * pi =4.5*4.5*3. 14=63.585 square decimeter.

Bottom circumference = diameter * pi =9*3. 14=28.26 decimeter.

Side area = bottom perimeter * height =28.26* 12=339. 12 square decimeter.

Iron sheet area = 1 bottom surface area+side surface area =402.705 square decimeter.

8,

Bottom circumference = diameter * pi =12 * 3.14 = 37.68cm.

Side area = bottom perimeter * height =37.68*55=2072.4 square centimeters.

Square area = top and bottom area +4 lateral area =12 *12 * 2+12 *16 * 4 = 288+768 =1056 square centimeter.

Paint area = side area+square area = 3128.4cm2.