Solution: Surface area = lateral area +2 bottom area.
Transverse area =? Lateral area of cylinder = perimeter of bottom circle × height =? 3. 14 x3x 2 x 6.5 = 122.46cm？
Bottom area =3. 14x3? x2 = 56.52cm？
Surface area =122.46+56.52 =178.98cm?
2. 2cm in diameter and 7cm in height. What is the lateral area?
Solution:? Surface area of cylinder S=πDh
≈3 14×7×2
=43.96cm？
3. 100 The surface of the oil drum should be painted, with a weight of 0.6kg per square meter. The bottom of each oil drum has a diameter of 40 cm and a height of 60 cm. 100 How much paint do you need?
Solution: The bottom radius of the oil drum is
40 ÷ 2 = 20cm = 0.2m.
The bottom area of the oil drum is
0.2× 0.2× 3.14 = 0.1256 (m2)
The horizontal area of the oil drum is
0.2× 2× 3. 14× 0.6 = 0.7536 (m2)
The area to be painted of the oil drum is as follows
0.1256× 2+0.7536 =1.0048 (m2)
Brush 100 oil drum for painting.
0.6×1.0048×100 = 60.288 (kg)
4. Make cylindrical ventilation pipes with iron sheets, each with a length of 80cm and a radius of 5cm. How much iron is used in 20 knots?
Solution: The main areas of Section 20 are
5× 2× 3. 14× 80× 20 = 50240 cm2.
iron sheet
5. What is the lateral area of a cylinder with a base diameter of 6cm and a height of 12cm and 100 such cylinders?
Solution:? Lateral area of cylinder = circumference of bottom circle × height = 5.3.14× 6×12×100 = 22,608 square centimeters.
Just press the formula! If you don't understand anything, please consult and hope to adopt it!