Finding the volume of a box problem 20

The side area is 78-15*2=48 (square centimeters).

In addition, the side area is also equal to the circumference of the bottom surface * height (assuming the sides of the box are spread out), so the height of the box is 48 16=3 (cm), so the volume of the box is 15*3=45 (cubic centimeters).

Suppose the length, width, and height of the box are a, b, and c, and the two sides of the bottom surface are a, b, and b(a>b) respectively. Rule.

There are two formulas, a*b=15 and 2*(a+b)=16, which are solved to get a=5 and b=3; Then according to the surface area formula.

2*(a*b+b*c+a*c)=78, i.e., 2*(15+3*c+5*c)=78, which can be solved to obtain c=3; then the volume is.

v a*b*c 5*3*3 45 cubic centimeters.

Note] "* means "multiplied".

Let the length, width and height of the cuboid be a, b, and c

According to the conditions, the following equations can be listed:

2（ab+ac+bc）=78……(1)

ab=15……(2)

2（a+b）=16……（3）

According to (2) and (3), a = 3 and b = 5

Substituting (1) yields c = 3

v = abc = 3 * 3 * 5 = 45 cubic meters.

Let the length be x, the width be y, and the height be z, there are x+y 16, x*y 15, the surface area s 2*(x*y+x*z+y*z) 78, the solution z is obtained, and the volume v x*y*z

Set the length, width and height of the bottom surface to a, b, c

a*b=15；

a+b)*2=16

Get a=5, b=3

15+3*c+5*c）*2=78

C = 3 volume = 3 * 4 * 3 = 45

Box volume = length x width x height.

v=abh=sh The length, width, and height of the box are a, b, and h, respectively

Compose. 1) Faces of a box: The planear polygons that enclose a closed geometry are called the faces of a polyhedron.

The box has 6 faces. Each of these faces is rectangular (there may be 2 opposite faces that are squares), and there are 3 pairs of opposite faces. Opposite faces have the same shape and equal area.

2) Edges of the box: The common edges of the two faces on the polyhedron are called the edges of the polyhedron. The box has 12 edges, of which there are 3 opposing edges, and each group of 4 opposite edges is parallel to each other and of equal length (there may be 8 edges of equal length).

3) The vertices of the cuboid: The cuboid has 8 coincidences and vertices, and the three edges that intersect at a vertex are called the cuboid Xiaokai staring length, width, and height. In general, the longer edge in the bottom surface is called long, the shorter edge is called wide, and the edge perpendicular to the bottom surface is called high.

Box volume = length x width x height which branch is buried.

v=abh=sh The length, width, and height of the cuboid are a, b, and h First of all, we need to know that the cuboid is a liquid mass composed of six rectangles, and then the opposite sides of either side of the cuboid are equal.

Then the cuboids all have length, width, and height. All have 8 vertices. There are 12 edges, the opposite edges and the length of the edges are equal, and the two adjacent edges are perpendicular to each other.

Once we know about the box, we should know:

The volume of the box = length x width x height.

The length, width, and height of the cuboid are a, b, and h, respectively.

Its volume will become: v=abh=sh (s is the base area).

Become the 27723rd fan.

The volume of the box is cubic decimeters.

The surface area of the box is 3 square decimeters.

If it's 3 pieces.

The volume of the box is cubic decimeters.

The surface area of a box is decimeter squared.

The calculation rules of multiplication Huai answer:

Digit alignment, starting from the right, use the number on each bit of the second factor to multiply the first factor, and multiply it by whichever digit you want, and the end of the number will be aligned with which digit of the second factor.

1. The number of tens is the two-digit multiplication method of 1: the unit of the multiplier is added to the multiplier, and the number is the front product, and the unit of the multiplier is multiplied by the unit of the multiplier, and the number is the back product, and the first ten are full.

2. The single digit is a two-digit multiplication method of 1: ten digits are multiplied by ten digits, the number is the previous product, the ten digits are added to the ten digits, and the number is then written, and the full ten digits are added to one, and 1 is added at the end.

3. The multiplication method of two lead oak digits with ten digits of the same single digit is different: the multiplier is added to the multiplier digit, and multiplied by the ten-digit integer, the product is used as the front product, and the single digit is multiplied by the single digit as the back product. ok

Box volume = length, width, height;

From the meaning, there will be length (width and height) = 209, 209 decompose the prime factor, get 11 19, 11 cannot be written as the sum of two prime numbers, 19 = 2 + 17, then, the volume is 11 17 2 = 374

The frontal area is: long

High. The upper area is: length and width. Correct.

surface and above. Sum of areas: length (width. High.

Because 209 = 11 * 19 then. Wide.

High. 11, either. Wide. High.

11 = 2 + 9 = 3 + 8 = 4 + 7 = 5 + 6, no matter how it is combined, there is a composite number.

19 = 2 + 17 = 3 + 16 = 4 + 15 = 5 + 14 = 6 + 13 = 7 + 12 = 8 + 11 = 9 + 10, there are only combinations of 2 + 17.

It's all prime numbers. So the length is 11 and the width is 11.

High. 2, 17, respectively

Its volume is: 11 17 2 = 374 (cubic centimeters).

The answer is 180

The largest rectangle in the circle is a square, and the diameter of the circle is known to be 6cm, which is the diagonal of the square.

Let the length of the square be a, a*a+a*a=6*6 (Pythagorean theorem), and get a*a=18

The volume of the cube = a*a*10=18*10=180

Let the bottom surface be square, and the volume will be the largest.

The diameter is equal to the diagonal of the square, so the side length of the square is 3 2, v=(32) 10=180 cubic centimeters.

The bottom surface of the box is a cylinder with a diagonal line of the rectangle and a base diameter of 6 cm.

There are bottom side lengths a, b; then 36=a2+b2 2ab ab 18 when ab=18 is maximum.

So the maximum volume is 18*10=180 cubic centimeters.

The volume is 250 cubic centimeters.

Cut the circle into a square with a side length of 5 cm (calculation method: the area of the circle is 9*pi, and the root number is rounded), so the volume of the cuboid is 5*5*10=250.

Because the area of the square in the circle is the largest, draw two diameters perpendicular to each other in the circle (the diameter length is 2*3=6cm), connect the intersection of the two diameters and the edge of the circle to form a square, and find the area of the square (which can also be regarded as a triangle) to get 18 square centimeters, 18*10=180, and the volume of the cuboid is 180 cubic centimeters.

I would like to adopt!!

3x6x10=180

To be as large as possible, then the circle must be divided into squares, with a diagonal length of 6 and an area of 3x6

Then, the length, width, and height of this long spike forest square are 8 centimeters, and the acres of Chaizhou are 7 centimeters and 3 centimeters.

The volume is: 8 7 3 = 168 (cubic centimeters).

The volume of the box = length * width * height.

Set them to x, y, and z respectively, and then find x, y, and z according to other known conditions to obtain the length, width, and height.

If there is only the known condition of volume, it cannot be calculated.