① What is the area ratio of a square to a circle if the perimeter of a square and a circle are equal? ② If the area of a square is 314 square centimeters, the area of a circle is______ Square centimeter

① What is the area ratio of a square to a circle if the perimeter of a square and a circle are equal? ② If the area of a square is 314 square centimeters, the area of a circle is______ Square centimeter

① Let their perimeter be s, then the side length of the square is S4, the area is equal to (S4) 2, the radius of the circle is S2 π, the area is equal to π × (S2 π) 2, in (S4) 2: π × (S2 π) 2 = π: 4. ② 314 × 4 △ π = 1256 △ 3.14, = 400 (square centimeter) answer: ① the area ratio of the square to the circle is π: 4, ② the area of the circle is 400 square centimeter

If the side length of a square is increased by 2 cm, the area of the new square will be 36 cm more than that of the original square, and the area of the original square will be 36 cm more
Less square centimeter?

The original square side length x cm
x²＋36＝﹙x＋2﹚²
x=8
8×8=64㎝²
The original square area is 64 cm and 178 cm;

If the side length of a square is increased by 2 cm, the area of the new square is 88 cm more than that of the original square. What is the area of the original square
Finding the area of a square

If you draw a picture, you can see that the increased area is composed of two equal rectangles and a square, and their sum is 88cm;,
Then 88-2x2 = 84, 84 △ 2 = 42cm, 42 △ 2 = 21cm, original area: 21x21 = 441cm & # 178;

The side length of a square is 10 cm. If its side length is increased by 2 cm, how many flat centimeters will its area increase

12*12-10*10=44

Barbie toy company wants to make a square toy cube with an area of 1.44 square centimeters. How many centimeters is its side length?
If we make a square packing box with a volume of 8 cubic centimeters for the new product magic cube, what is the side length of this kind of packing box?

Because the area of a square = side length x side length, and 1.44 = 1.2x1.2
So his side length is 1.2cm
Because the volume of a square = edge length x edge length x edge length, and 8 = 2x2x2
So the side length of this kind of packing box should be 2cm

The fourth grade math problem is a square children's playground. When it is rebuilt, the side length will be increased by 5 meters to make the side length 30 meters. How many square meters will the playground increase after the reconstruction
emergency

The original side length is 30-5 = 25m
The increased area is the current area - the original area = 30 * 30-25 * 25 = 275 square meters

The height of a cylinder is equal to the circumference of its bottom. If the height is reduced by 2cm, the surface area will be reduced by 12.56cm
Surface area of

Let the circumference be c
The reduced area is
2C
If you take 12.56 as 4 π, that's it
2C=4π
C=2π
Bottom radius
r=1
What is the surface area of the cylinder
2π+4π^2

1. Master Wang wants to process a cylindrical tin barrel with a bottom and no cover. The barrel is 6.28 decimeters high, and its side is just a square after unfolding. How many square meters of tin will master Wang prepare?
2. The circumference of the bottom surface of a cylinder is equal to its height. If the height is increased by 4 cm, the surface area will be increased by 25.12 square cm. Find the surface area of the cylinder
Once adopted, 20 points will be awarded
I can't understand the symbols. Or words.

1. This square area = 6.28 decimeter square = 6.28 * 6.28
The perimeter of the bottom surface = 6.28 decimeters high, so the radius of the bottom surface is:
6.28/(3.14*2)
Then, the bottom area is:
3.14*[6.28/(3.14*2)]^2
Master Wang should prepare at least one piece:
3.14*[6.28/(3.14*2)]^2+6.28*6.28
=3.14+39.44
=42.58 square decimeters
2. Let's set the height x cm
{(X+4)*X+2*3.14[X/(3.14*2)]^2}-{X^2+2*3.14*[X/(3.14*2)]^2}=25.12
The solution is as follows
X = 6.28 cm
So the surface area of this cylinder is:
X^2+3.14*[X/(3.14*2)]^2
=6.28*6.28+2*3.14*[6.28/6.28]^2
=39.44+6.28
=45.72 square centimeter

1. Calculate the surface area and volume of the cylinder below. (unit: cm)
Radius: 2.4cm height: 4cm

Side area: 2.4 × 2 × 3.14 × 4 = 60.288 (CM & # 178;)
Bottom area: 3.14 × 2.4 & # 178; = 18.0864 (CM & # 178;)
Surface area: 60.288 + 18.0864 × 2 = 96.4608 (CM & # 178;)
Volume: 3.14 × 2.4 & # 178; × 4 = 72.3456 (CM & # 179;)

Ask a mathematical problem, a cone with a height of 9cm, and change it into a cylinder with the same bottom area. What is the height of the cylinder
Ask a math problem
A cone with a height of 9cm is changed into a cylinder with the same bottom area. What is the height of the cylinder in cm
I want formula, there are formula in the bonus

The key is that the volume of a cone is equal to that of a cylinder
Cone volume = bottom area * height / 3
Cylinder volume = base area * height
Here the two bottoms are equal in area
So the cylinder is 3cm high