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In a round flower bed, half a circle, 141.3m, the radius of this flower bed is
Because the circumference formula of a circle is 2 π R, the circumference of a semicircle is half of the whole circle, so π × r = 141.3, r = 141.3 △ π = 141.3 △ 3.14 = 45m, R is the radius of the circle
The radius of a round flower bed is 3M. Now the worker's uncle has widened 1m around him. How many square meters has the area increased?
Current radius: 3 + 1 = 4 (m)
Area increase: 3.14 × 4 × 4-3.14 × 3 × 3 = 21.98 (M2)
In the middle of a circular grassland with a perimeter of 25.12 meters, build a circular flower bed with a radius of 3 meters. What is the area of the remaining grassland in square meters
25.12 ﹣ 3.14 ﹣ 2 = 4m
3.14 × 4-178; - 3.14 × 3-178; = 21.98 square meters
What is the property of the side of a right triangle with an angle of 30 degrees____________________
In a right triangle, the right side of a 30 ° angle is equal to half of the hypotenuse
How to make a right triangle with ruler and gauge
Methods:
1. Make ∠ mon = 90 ° (two vertical straight lines can also be made with ruler)
2. Intercept OA = 1 unit length on OM
3. Take a as the center of the circle, draw an arc with 2 units of radius, and intersect on at point B
4. Connect ab
Then: ∠ oba = 30 ° (according to the fact that the right side of a right triangle is equal to half of the hypotenuse, the acute angle of the right side is 30 °)
A square nursery covering an area of 1 hectare, the length of each side is extended by 100 meters, how many hectares of nursery area will be increased?
In order to solve this problem, we need to know the unit conversion first
1 hectare = 10000 square meters = 100 meters * 100 meters (100 meters is the side length of a square);
Now the length of each side is increased by 100 meters, that is, the new side length of the square is 100 meters + 100 meters = 200 meters;
The area after side length change is 200m * 200m = 40000 M2 = 4 ha;
The nursery area is increased to 4 ha - 1 ha = 3 ha
A square nursery covering an area of 4 hectares will increase the side length by 200 meters. How many hectares will the nursery increase?
4 ha = 40000 M2
So the side length of a square is 200 meters
When the length of each side is increased by 200 meters, the length of a square is 400 meters
The area of the square is 160000 square meters = 16 hectares
Increased 16-4 = 12 ha
How many hectares will a square nursery cover if its side length is increased by 100 meters?
The square nursery covers an area of 1 hectare with a side length of 100 meters
Current area: 110 × 110 = 12100 square meters
12100 M2 = 1.21 ha
A: slightly
In a right triangle, there is an angle of 45 degrees, a height of 2.6 meters, oblique length and bottom length and area
I didn't go to school. I want to find the two sides of the triangle in detail. Thank you for your urgent need
Because it is a right triangle with an angle of 45 degrees, the bottom edge is equal to the height of 2.6. According to the Pythagorean theorem, calculate the sum of squares of two right angles and then square, that is, the length of the hypotenuse; the area is half of the product of two right angles
How to calculate the oblique length of a triangle
See what triangle, general sine and cosine theorem, right triangle with Pythagorean
RELATED INFORMATIONS
- 1. In the middle of a circular grassland with a girth of 25.12 meters and a flower bed with a radius of 2.5 meters, how many square meters of grassland are left?
- 2. When the side length of a square increases by 3cm, its area increases by 39cm2. The side length of the square is () A. 5cmB. 6cmC. 8cmD. 10cm
- 3. The area of a square flower bed is 225 square meters. How many meters is its side length?
- 4. After adding 3cm to the two adjacent sides of a square, we get a new square. The area of the new square is 39 square centimeters larger than that of the original square. What's the area of the original square?
- 5. A circular pool with a radius of 6 meters is surrounded by a circular path with a width of 1 meter. How many square meters is the area of this path?
- 6. Guangming primary school built a semicircular flower bed along a wall. The fence around the flower bed is 31.4 meters long. How many square meters does the flower bed cover?
- 7. The school has built two cylindrical flower beds. The inner diameter of the flower beds is 3 meters, and the height is 0.8 meters. If the height of the filling soil is 0.5 meters, How many cubic meters of soil are needed for the two flower beds?
- 8. Street Park to build a diameter of 12 meters of circular flower bed, around with tiles paved a 3 meter wide path, each tile area is 0.9 square meters Street Park to build a diameter of 12 meters of circular flower bed, around with tiles paved a 3 meter wide path, the area of each tile is 0.9 square meters, how many tiles to use to lay this path?
- 9. There is a flower bed 25 meters long and 20 meters wide. If a 3 meter wide path is built around the flower bed (as shown in the figure), what is the area of the path?
- 10. It is known that the length of rectangular ABCD is 30cm and the width is 20cm. A proper plane rectangular coordinate system is established, and the coordinates of a, B, C and D are obtained first Then the rectangle is made in the rectangular coordinate system ABCD.Thank you
- 11. The diameter of a round flower bed is 8m. How many meters is the perimeter of the flower bed and how many square meters does it cover
- 12. There is a round flower bed in the park, with a diameter of 30 meters. Grandfather Zhang ran around the flower bed for 5 laps in morning exercise. How many meters did he run this time?
- 13. As shown in the picture, a square street garden, the middle is a square flower bed, surrounded by a path, the side length of the flower bed is 12 meters, the width of the path is 1 meter What's the area of the hotel?
- 14. A square flower bed should be built in the park, and a 2m wide lawn should be laid beside the flower bed. The lawn area is 96 square meters. What is the total area of the flower bed and lawn? In the simplest way. No equations
- 15. As shown in the picture, the shape of a 40 meter long vegetable greenhouse is a semi cylindrical shape with a 3-meter-high semi-circular brick wall at both ends. The vegetable greenhouse is covered with plastic film until the end How many square meters less plastic film is needed? How many cubic meters of space is the whole vegetable greenhouse?
- 16. The length of the three wires is 215 meters. One third of the first wire is used, three fifths of the second wire is used, and three fourths of the third wire is used How long are the three wires?
- 17. Cut a 1997 cm long wire into 199 cm and 177 cm long wires, and the rest is at least 100 cm long______ Cm
- 18. The length of the two wires is 33 meters in total. The first wire takes 2 / 3, the second 12 meters, and the remaining length of the second wire is 1 / 2 of the remaining length of the first wire?
- 19. How many meters does the length of carpet need at least I won't spend the picture
- 20. Carpet is laid on the surface of stairs with height of 3 and slope length of 5. It is known that the width of stairs is 2m, and the price of carpet is 5 yuan / m. how much does it cost to lay six identical stairs