How much DM is the height of a rectangular iron bar with a bottom area of 1.08dm2 cast from a square iron block with an edge length of 1.2m?

How much DM is the height of a rectangular iron bar with a bottom area of 1.08dm2 cast from a square iron block with an edge length of 1.2m?

Height = 12 & # 179; △ 1.08 = 1600 decimeters

A square iron block with 6cm edge length is cast into a cuboid which covers an area of 30dm2. The height of the cuboid is () DM

6cm = 0.6dm
0.6 × 0.6 × 0.6 △ 30 = 0.0072 decimeter

Take a square iron block with the edge length of 6dm to make a cuboid with an area of 30 square decimeters. The height of the cuboid is () DM

The process of piecing together is like kneading rubber clay, and the volume will not change
(6*6*6)/30
=216/30
=7.2

The circumference of a rectangle is 25 cm, and the ratio of length to width is 5:2. How many cm are the length and width of the rectangle? What is the area

The circumference of the rectangle is 25 cm,
The sum of length and width is 12.5 cm,
The length is 12.5 △ (5 + 2) × 5 = 125 / 14 cm
The width is 12.5 △ (5 + 2) × 2 = 25 / 7 cm
Area: 125 / 14 × 25 / 7 = 3125 / 98 square centimeter

The circumference of a rectangle in grade five is 240 meters, and its length is 1.4 times of its width. How many meters are the length and width of the rectangle

Length = 240 ／ 2 ／ (1.4 + 1) × 1.4 = 70
Width = 240 ／ 2 ／ (1.4 + 1) × 1 = 50

Fifth grade mathematics problem (a rectangle, the length and width are increased by 2 cm, the area is increased by 44 square cm, the original rectangle perimeter is how much?

Let the width of the original occasion be x cm, y cm
So now it's x + 2 cm, y + 2 cm
Area increase (x + 2) (y + 2) - xy = 44
xy+2x+2y+4-xy=44
2x+2y=40
So the circumference is 40 cm

Place two semicircles with radius of 4cm and 3cm respectively as shown in the figure, and calculate the perimeter of the shadow part
 

Let me give you an answer: the perimeter of the shadow part in the figure is divided into six parts: (as shown in the figure) combination of 1 and 4: it is the half perimeter of the big circle: 2 * 3.14 * 4 and then half = 12.56cm3 and combination of 6: it is the half perimeter of the small circle: 2 * 3.14 * 3 and then half = 9.42cm2 part length: the radius of the big circle: 4cm5 part length: the diameter of the small circle minus the radius of the big circle:

Place two semicircles with radius of 3cm and 2cm as shown in the figure, and calculate the perimeter of the shadow part ()
A. 18.7 cm B. 19 cm C. 10 cm D. 19.7 cm

3.14 × 3 × 2 / 2 + 3.14 × 2 × 2 / 2 + 3 + 2 × 2-3, = 9.42 + 6.28 + 3 + 1, = 19.7 (CM), a: the perimeter of the shadow is 19.7 cm

Place two semicircles with radius of 3cm and 2cm as shown in the figure, and calculate the perimeter of the shadow part ()
A. 18.7 cm B. 19 cm C. 10 cm D. 19.7 cm

3.14 × 3 × 2 / 2 + 3.14 × 2 × 2 / 2 + 3 + 2 × 2-3, = 9.42 + 6.28 + 3 + 1, = 19.7 (CM), a: the perimeter of the shadow is 19.7 cm

As shown in the figure, the radius of the large semicircle is 3.5cm, and the diameter of the small semicircle is 5cm
can't?

3.5*2=7
7 * 3.14 + 5 * 3.14 = shadow perimeter