![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
Divide a circle into 16 parts averagely and make it into an approximate rectangle. The perimeter of the rectangle is 8 cm longer than that of the original circle. The area of the original circle is______ Square centimeter
The radius of the circle: 8 △ 2 = 4 (CM), the area of the circle: 3.14 × 42 = 50.24 (square cm), answer: the area of the original circle is 50.24 square cm, so the answer is: 50.24
Divide a circle into 16 parts averagely and make it into an approximate rectangle. The perimeter of the rectangle is 8 cm longer than that of the original circle. The area of the original circle is______ Square centimeter
The radius of the circle: 8 △ 2 = 4 (CM), the area of the circle: 3.14 × 42 = 50.24 (square cm), answer: the area of the original circle is 50.24 square cm, so the answer is: 50.24
A rectangular cardboard is 8 cm in length and 5 cm in width, one or two of which are in diameter. After cutting off the two semicircles, what are the perimeter and area of the remaining figures?
Perimeter: 8x2 + 3.14x5 = 31.7
Area: 8x5-3.14x (5 divided by 2) = 20.375
A circular paperboard, the inner circle radius is 3 cm, the outer circle diameter is 10 cm, the area of this circular paperboard is____ square centimetre
10 △ 2 = 5cm
Ring area: 3.14 × (5 & # 178; - 3 & # 178;) = 50.24 square centimeter
The radius of the inner circle of a ring is 3 meters, and the circumference of the outer circle is 37.68 meters. How many square meters is the area of the ring?
The radius of the outer circle is: 37.68 △ 3.14 △ 2 = 12 △ 2, = 6 (meters), the area of the ring is: 3.14 × 62-3.14 × 32 = 3.14 × (36-9), = 3.14 × 27, = 84.78 (square meters), a: the area of the ring is 84.78 square meters
What is the area of a ring with an outer radius of 2 decimeters and an inner circumference of 6.28 decimeters?
The circumference of the inner circle is 6.28 decimeters, and the radius of the inner circle is 6.28 / (3.14 * 2) = 1 decimeter
Area of ring = outer circle area inner circle area
=2^2*3.14-1*1*3.14
=3*3.14
=9.42 (square decimeter)
After cutting a piece of round cardboard, put it together into an approximate rectangle with the width equal to the radius and the area equal. The perimeter of the rectangle is 24.84 decimeters
After cutting a piece of round cardboard, put it together into an approximate rectangle with the width equal to the radius and the area equal. The perimeter of this rectangle is 24.84 decimeters. How many square decimeters is the original area of this round cardboard?
Suppose the rectangle is a square (that is, the circle is cut in half), then the diameter of the circle is 24.84/4 = 6.21
Circular area = 3.14 * (6.21 / 2) ^ 2DM
The radius of the outer circle of a ring is 2 cm, and the circumference of the inner circle is 6.28 cm
If you can write a formula, you have to write it,
6.28÷3.14÷2=1（cm）
1×1×3.14=3.14（cm²）
2×2×3.14=12.56（cm²）
12.56-3.14=9.42（cm²）
The area of this ring is 9.42 CM & sup2;
What is the area of a ring with an inner radius of 3cm and an outer circumference of 37.68?
Inner circle radius 25.12 △ 3.14 △ 2 = 4cm
Outer circle radius 37.68 △ 3.14 △ 2 = 6cm
Ring area 3.14 × (6 × 6-4 × 4)
=3.14×20
=62.8 square centimeters
A square with a side length of 4cm has the same area and perimeter?
A: it's wrong
Although the number of perimeter and area is 16, the unit of side length 16 is centimeter, and the unit of area 16 is square centimeter
RELATED INFORMATIONS
- 1. A square with a side length of 5cm has a circumference of () and an area of ()
- 2. The perimeter ratio of a rectangle to a square is 6:5, and the length to width ratio of a rectangle is 7:5. What is the area ratio of the rectangle to the square Don't worry about the equation
- 3. If a square is enlarged by 3:1, its area will be expanded by 3 times______ (judge right or wrong)
- 4. If one side of a rectangle is equal to 3m + 2n and the other side is M-N smaller than it, the perimeter of the rectangle is______ ．
- 5. A rectangular piece of paper 50 cm in length and 25 cm in width is cut off from four corners, and a square 5 cm in length is made into a carton. What is the volume of the carton
- 6. A rectangular sheet of iron is 24 cm long. After subtracting the square with side length of 3 cm from the four corners, it is welded into a rectangular sheet iron box without cover. The volume of the box is 486 cubic cm. How many cm is the width of the original rectangular sheet iron? Good points for giving reasons
- 7. A square iron sheet, four corners, cut off four small squares of the same size, and fold them into a cuboid box with a bottom side length of 50 cm and a volume of 45000 cubic cm. Find out the side length of the original square iron sheet. (use equation solution)
- 8. A 30 cm long, 20 cm wide rectangular cardboard four corners to a side length of 5 cm cube, and then fold along the dotted line into a cuboid What's the volume in cubic centimeters?
- 9. There is a 18cm wide rectangular iron plate. After cutting the square with 4cm side length at the four corners, it is welded into an iron box without feeding. The known volume of the iron box is 760 cubic cm How many square centimeters is the original iron plate area?
- 10. A rectangular iron plate is 20 cm long and 14 cm wide. In this way, the cube with a side length of 2 cm is cut off from the four corners, and then it is made into a lidless zygote. What is the volume of this box
- 11. A circumference of 16 decimeters square cardboard, cut into () the largest circle, minus the cardboard has () square decimeters
- 12. When a = 17.4, B = 2.6, the remaining area is () A.289 B.298 C.296 D.269
- 13. How many biggest circles can be cut out on a rectangular paperboard 20 cm long and 2 cm wide? What is the area of each circle? What's the area of the rest?
- 14. Cut the largest circle from a piece of iron 8 decimeters long and 6 decimeters wide. How many square decimeters is the remaining scrap area? If you're right, I'll take 50 extra
- 15. The diameter of a circle is 8 decimeters. Cut it into the largest square. What is the minus area Please explain why
- 16. The circumference of the rectangular abccd is 16 meters. On each side of the rectangular abccd, draw a square with that side as the side length. It is known that the sum of the four squares is 68 Square meter, find the area of ABCD
- 17. How many square decimeters is the area of a rectangle made of two identical squares reduced by 20 centimeters in circumference
- 18. The perimeter of a rectangle is 72 meters. If its width increases by 1 / 4 and its length decreases by 1 / 8, and its perimeter remains the same as the original, what is the area of the rectangle?
- 19. It is known that the perimeter of the sector is 20 cm and the area is 16 square cm. The radius of the sector is calculated
- 20. A is the point of negative one on the number axis. Move a to the left two unit lengths along the number axis to reach B, then the number represented by B is