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How much cardboard is needed to make 10 rectangular cartons with 81 square centimeter bottom area and 6 centimeter height
(no cover)
9 × 6 × 4 = 216 (cm2)
216 + 81 = 297 (cm2)
297 × 10 = 2970 (cm2)
(covered)
216 + 81 × 2 = 378 (cm2)
378 × 10 = 3780 (cm2)
Use cardboard to make a rectangular paperless carton with a square bottom, a square centimeter bottom area and a height of 5cm. How much cardboard should be used at least?
How big is the square on the bottom? Does it mean the area of cardboard or the surface area of cuboid? Because there will be edge material when cutting and edge folding. I don't understand
The length of the rectangle is reduced by 3 cm and becomes a square. Its area is reduced by 21 square meters
The width of the original rectangle is 21 / 3 = 7 cm
The length of the original rectangle is 7 + 3 = 10 cm
Original area = 10 * 7 = 70 square centimeter
If the length of a cuboid is increased by 2 cm, the area will be increased by 10 square cm; if the length is decreased by 3 cm, a square will be obtained. What is the circumference of the original rectangle?
The width is 10 △ 2 = 5cm
So the length is 5 + 3 = 8 cm
The circumference is (8 + 5) × 2 = 26 cm
A cuboid cardboard is 8 cm long and 6 cm wide. Fold it into the side of a cuboid with a square bottom area
What is the bottom area of the cuboid
4 or 9 / 4?
If it is the side of a cuboid, then the length is the side of the square, then the side of the square is 8 / 4 = 2, and its area is 2 ^ 2 = 4
Take the width as the side of the square, then the side of the square is 6 / 4 = 3 / 2, and its area is (3 / 2) ^ 2 = 9 / 4
Unfolding the side of a cuboid is a square with a side length of 8 cm. The surface area of the cuboid is () flat
Unfolding the side of a cuboid is a square with 8 cm side length. The surface area of the cuboid is (72) square cm
Because: unfolding the side of a cuboid is a square with side length of 8 cm, and the bottom of the cuboid is a square with side length of 2 cm
2 × 2 × 2 + 8 × 8 = 72 (cm2)
Cut a 10 cm long and 8 cm wide rectangular cardboard into the same square, and then fold it into a cuboid box without cover
Do you have the largest side area of the box? Yes, ask for the maximum value and minus the side length of the square; no, please explain the reason
2. If you subtract two identical squares and rectangles from the sides of the rectangular cardboard, and then fold them into a rectangular box with a cover, is there any case where the side area is the largest? Yes, ask for the maximum value and subtract the side length of the square; no, please explain the reason
List the volume function and find the derivative
A rectangular iron plate, 75 cm long and 8 cm wide, covers an area of () square centimeter or () square decimeter
1. On one side of the sidewalk in front of the teaching building, the school planted 18 trees every 3 meters from one end of the sidewalk to the other end. The sidewalk of the school is () meters.
2. There is a round garden with a circumference of 4800 meters. Jasmine flowers are planted around the garden, one plant every 6 meters, with a total of () jasmine flowers planted.
A rectangular iron plate, 75 cm long and 8 cm wide, has an area of (600) square centimeters, or (6) square decimeters
1. The school planted 18 trees every 3 meters on one side of the sidewalk in front of the teaching building
2. There is a round garden with a circumference of 4800 meters. Jasmine flowers are planted around the garden. One jasmine flower is planted every 6 meters. There are 800 jasmine flowers in total
A rectangular iron plate with an area of 800 square centimeters is cut out on a square iron plate with a side length of 1 meter, so that the length is 20 cm more than the width. How long is the length and the width of the rectangular iron plate? Quadratic equation of one variable
Let the rectangle be x cm in length and x-20 cm in width
X (x-20) = 800. The solution is x = 40 and x = - 20 (discard)
x-20=20
A: the length is 40 cm and the width is 20 cm
Cut out the largest circle from a rectangular sheet of iron 20 cm long and 8 cm wide. The circumference of the circle is () cm, and the remaining area of the rectangle is () square centimeter
Cut out the largest circle on the rectangular sheet of iron 20 cm long and 8 cm wide. The circumference of the circle is (8 * 3.14 = 25.12) cm, and the remaining area of the rectangle is (160-16 * 3.14 = 109.76) square centimeter
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- 1. The bottom is a square cuboid carton. Unfold its side to get a square with a side length of 20 cm. How much cardboard does this cuboid carton need at least
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