Use a 54 cm long wire to form a rectangle. If the length is twice the width, what is the length and width of the rectangle? What's the area?

Use a 54 cm long wire to form a rectangle. If the length is twice the width, what is the length and width of the rectangle? What's the area?

So the length of the rectangle is 9 × 2 = 18 (CM), and the area is 18 × 9 = 162 (CM). A: the length of the rectangle is 18 cm, the width is 9 cm, and the area is 162 square cm

A 50 cm long wire is bent into a rectangle. Let one side of the rectangle be x (CM) long and its area be y (cm2), then the functional relationship between Y and X is ()
A. y=-x2+50xB. y=x2-50xC. y=-x2+25xD. y=-2x2+25

Let one side of the rectangle be xcm, and the other side be (25-x) cm, with the area y = x (25-x) = - x2 + 25X

With 22cm long wire, fold it into a rectangle with an area of 28cm square. How long is the rectangle?

Let the length of the rectangle be x cm
x(22÷2-x)=28
That is X & # 178; - 11x + 28 = 0
(x-4)(x-7)=0
x1=4,x2=7
When x = 4, 11-x = 7
When x = 7, 11-x = 4
The length of the rectangle is seven centimeters

There is a wire that can be enclosed into a square with a side length of 6.28 decimeters. If this wire is used to enclose a circle, what is the area of the circle?

There is a piece of iron wire that can form a square with a side length of 6.28 decimeters,
The length of the wire is 4 * 6.28 decimeters
If you use this wire to make a circle
Circle radius r = 4 * 6.28 decimeters / 2 π≈ 4 decimeters
The area of the circle is π * 4 ^ 2 = 16 π square decimeter ≈ 50.27 square decimeter

Use a 6.28 decimeter long wire to form a circle. How many square decimeters is the area of the circle?

The length of a wire is the circumference of a circle,
Radius = 6.28 / (2 * 3.14) = 1
Area = 1 * 1 * 3.14 = 3.14 square decimeters

With a wire can be surrounded into a side length of 9.42 decimeters square, if the wire into a circle, the circle area is how many square decimeters

=(9.42 × 4 ﹣ 2 ﹣ 3.14) ^ 2 × 3.14 = 113.04 square decimeters

A wire can be enclosed into a square with a side length of 9.42 meters

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A 6.28-meter-long wire, surrounded by a circle, the area of the circle is______ Square meters

The radius of the circle is: 6.28 △ 3.14 △ 2 = 1 (m); the area of the circle is: 3.14 × 12 = 3.14 × 1 × 1 = 3.14 (M2); answer: the area of the circle is 3.14 m2. So the answer is: 3.14

The wire with length of 1 is divided into two sections and enclosed into a square and a circle respectively. In order to minimize the sum of the area of the square and the circle, the perimeter of the square should be___ ．

Analysis: let the perimeter of the square be x, then the perimeter of the circle is 1-x, the radius r = 1-x2 π. S positive = (x4) 2 = x216, s circle = π · (1-x) 24 π 2. S positive + s circle = (π + 4) x2-8x + 416 π (0 < x < 1). When x = 4 π + 4, there is a minimum value. Answer: 4 π + 4

The wire with length of 1 is divided into two sections and enclosed into a square and a circle respectively. In order to minimize the sum of the area of the square and the circle, the perimeter of the square should be___ ．

Analysis: let the perimeter of the square be x, then the perimeter of the circle is 1-x, the radius r = 1-x2 π. S positive = (x4) 2 = x216, s circle = π · (1-x) 24 π 2. S positive + s circle = (π + 4) x2-8x + 416 π (0 < x < 1). When x = 4 π + 4, there is a minimum value. Answer: 4 π + 4