A rectangular block of wood, cut from the upper and lower parts of the cuboid 3 cm and 2 cm high, will become a cube, the surface area reduced by 120 square meters Centimeter, what's the original volume? It's very detailed. No equation,
The surface area is reduced by side area, 4 × side length × (3 + 2) = 120 square centimeters
Side length = 120 / 4 × (3 + 2) = 120 / 20 = 6cm
The original volume = side length × side length × (3 + 2 + side length) = 6 × 6 × (3 + 2 + 6) = 396 cubic centimeters
A cuboid wood block is cut from the upper part and the lower part of the cuboid with a height of 3cm and 2cm respectively to form a cube with a surface area reduced by 120 square percent
Suppose the base perimeter of the cuboid is x cm, then the reduced surface area is the base perimeter * (3 + 2) = 120, the base perimeter = 24 square cm, the side length is 24 / 4 = 6 cm, the height of the original cuboid is 6 + 3 + 2 = 11 cm, the base area is 6 * 6 = 36 square cm, the volume of the original cuboid is
Cuboid wood blocks, cut from the lower and upper parts of the cuboid 2 cm and 4 cm high, will become a cube, the surface area of 120 square centimeters less
What is the volume of the original cuboid
After cutting the cuboids 2 cm and 4 cm high from the lower and upper parts respectively, the area of the bottom surface is not small. The reduction is the area of the side surface with the height of (2 + 4) cm divided by the height of 120 / (2 + 4) = 20 cm,
The side length of the bottom surface is 20 / 4 = 5cm, so the volume of the original cuboid is
5 * 5 * (5 + 4 + 2) = 275 CC
A cuboid wood block, cut from the lower part and the upper part of the cuboid 3 cm and 2 cm high, will become a cube, the surface area reduced by 120 square centimeters, the original cuboid volume is how many cubic centimeters?
The volume of cuboid is 396 cubic centimeter, which is 120 △ 4 △ 2 + 3 = 30 △ 5 = 6 (CM); 6 × 6 × (6 + 5) = 36 × 11 = 396 (cm3)
As shown in the figure, the circumference of the rectangle ABCD is 16 cm. Take ABCD as the edge and make square abef and adgh outwards. If the area sum of square abef and adgh is 40
Area of ABCD
12
Make a square cdef in the gold rectangle ABCD to get a small rectangle abef. Is the rectangle ABFE also gold
Give a detailed reason
AB / BC = (√ 5-1) / 2CD = CFBC = BF + CF = BF + CD, so AB / (BF + CD) = (√ 5-1) / 2 (BF + CD) / AB = 2 / (√ 5-1) because CD = AB, so BF / AB + 1 = 2 / (√ 5-1) = 2 (√ 5 + 1) / 4 = (√ 5 + 1) / 2BF / AB = (√ 5 + 1) / 2-1 = (√ 5-1) / 2, so it is a golden rectangle
Divide a circle into several parts, and then form an approximate rectangle. It is known that the circumference of the rectangle is 41.4cm. Then the circumference and area of the circle are different
How many?
Write simple, no need to teach, write formula directly
Circle radius = 41.4 / (3.14 * 2 + 2) = 5
Circumference = 3.14 * 2 * 5 = 31.4
Area = 3.14 * 5 * 5 = 78.5 square centimeter
When drawing, the distance between the two feet of the compass is 2.5cm, and the circumference of the drawn circle is () cm
10
When the distance between the two feet of the compass is 3.5cm, the circumference of the circle drawn is () cm
21.98
When the distance between the feet of a compass is 2.5cm, the circumference of the circle drawn is______ .
C = 2 π R, = 2 × 3.14 × 2.5, = 15.7 (CM). Answer: the circumference of the circle is 15.7 cm. So the answer is: 15.7 cm