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The base and height of a triangle are equal to the radius of the circle. If the area of the circle is 31.4 square decimeters, the area of the triangle is () square decimeters; if the area of the triangle is 10 square decimeters, the area of the circle is () square decimeters
If the area of the circle is 31.4 square decimeters, the area of the triangle is (5) square decimeters;
31.4 ﹣ 3.14 ﹣ 2 = 5 square decimeters
If the area of a triangle is 10 square decimeters, the area of a circle is (62.8) square decimeters
10 × 2 × 3.14 = 62.8 square decimeters
Divide a circle into four parts. Draw a triangle in one part. The area of the triangle is 25 square decimeters. What is the area of the circle?
If the area of the triangle is 25 square decimeters, then the area of the triangle = R & # / 2 = 25
r²=50
So the circle area = π R & # 178; = 50 π = 50 * 3.14 = 157 square decimeters
Three practical problems in Grade 6
There are three departments in an organization. Department a has 84 employees, Department B has 56 employees, and department C has 60 employees. If each department cuts its staff according to the same proportion, so that only 150 employees are left in the organization, how many employees should Department C leave?
For two pieces of copper zinc alloy, the weight ratio of the first piece to the second piece is 2:1, the weight ratio of the first piece of copper to zinc is 1:2, and the weight ratio of the second piece of copper to zinc is 5:4?
The top half of a sealed water bottle is conical and the bottom half is cylindrical. The bottom diameter is 8 cm. The height of the water bottle is 12 cm and the height of the liquid level in the bottle is 6 cm. When the water is inverted and the height of the liquid level in the bottle is 8 cm, what is the volume of the water bottle?
(1) The total number of employees in this department is 84 + 56 + 60 = 200. If there are 150 employees left after layoffs, the number of employees will be 200-150 = 50 and the proportion of layoffs will be 50 / 200 = 1 / 4. If there are 60 employees in department C and the number of employees will be 60 * 1 / 4 = 15, the number of employees left will be 60-15 = 45
(2) Suppose the weight of the second block is x, then the first block is 2x, the ratio of copper to zinc of the first block is 1:2, then the copper is 1 / 3 * 2x = 2 / 3x, the zinc is 2 / 3 * 2x = 4 / 3x, the ratio of copper to zinc of the second block is 5:4, then the copper is 5 / 9x, the zinc is 4 / 9x, the ratio of copper to zinc after fusion is (2 / 3x + 5 / 9x): (4 / 3x + 4 / 9x) = 11:16
(3) If the total height of the water bottle is 12cm and the liquid level is 8cm after inversion, the total volume is equal to the liquid volume + 4cm high cylinder volume. If the liquid volume is 6cm high cylinder volume, the total volume = 10cm high cylinder volume = π R & sup2; H = 160 π
A and B both produce the same kind of parts. A produces 8 more parts per hour than B. now, a is required to produce 168 such parts and B 144 such parts. Which of them will finish the task first?
A's production time: (168-144) △ 8 = 24 △ 8 = 3 (hours); B's production time: (168 △ 3-8) = 144 △ 48 = 3 (hours). A: both of them complete the task at the same time
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