The diameter of a circle is 8 decimeters. Cut it into the largest square. What is the minus area Please explain why

The diameter of a circle is 8 decimeters. Cut it into the largest square. What is the minus area Please explain why

The radius of the circle is four decimeters
The largest square is divided into four small isosceles right triangles by its two diagonals,
The area of each small isosceles right triangle
=4*4/2、
=8 square decimeters
The area of the largest square is 8 * 4 = 32 square decimeters
Area subtracted
=Area of a circle - the area of the largest square
=3.14*4*4-32、
=50.24-32、
=18.24 square decimeters

1. The diameter of a circle is 8 decimeters, cut it into the largest square, how many square decimeters is the area cut out?
2. Cut a round piece of paper into an approximate rectangle. The width of the rectangle is 4cm. What's the circumference and area of the circle?

1, diagonal of the largest square = diameter = 8 decimeters
Therefore, the square area S1 = 8 * 8 / 2 = 32 square decimeters
The area of circle S2 = 3.14 * 8 / 2 * 8 / 2 = 3.14 * 16 = 50.24 square decimeters
Then the area to go forward is 50.24-32 = 18.24 square decimeters
two
Width of rectangle = radius of circle = 4cm
Circumference of circle = 3.14 * 4 * 2 = 25.12 cm
Area = 3.14 * 4 * 4 = 50.24 square centimeter

The diameter of a circle is 8 decimeters. Cut it into the largest square. How many square decimeters is the area cut?

The area of the largest square is: 8 & # 178; △ 2 = 32 (square decimeter)
The cut area is (8 △ 2) &# 178; x3.14-32 = 50.24-32 = 18.24 (square decimeter)
Idea: if the diameter of the circle is 8 decimeters and the diagonal of the largest square is 8 decimeters, then the area of the square is 8 × 8 △ 2 = 32 square decimeters, and the area of the circle is 16 π, then the area of the circle is 16 π - 32 = 16 × 3.14 - 32 = 18.24 square decimeters

A square with a side length of 6 decimeters, if each side is increased by 2 decimeters, how much more is its area than the original?

It can be calculated
（6+2）*（6+2）-6*6=8*8-6*6=48-36=12
What do not understand can continue to ask, online at any time, etc

A square with a side length of 6 decimeters has an area of
A. 24 square decimeters b.36 square decimeters c.36 square centimeters d.36 decimeters

Answer B 6 × 6 = 36 (square decimeter), select B

How many square decimeters is the area of each circle cut out by cutting four circles as equal as possible from a square sheet of iron with a side length of 6 decimeters?

Cut out four circles of the same size as possible, the diameter of which is equal to half of the side length of the square
Radius of circle = (6 / 2) / 2 = 1.5 decimeters
The area of each circle is 3.14 * 1.5 * 1.5 = 7.065 square decimeters

Cut two equal circles as large as possible from a square sheet of iron with a side length of 6 decimeters. What is the area of the remaining sheet of iron in square decimeters?

6 × 6-3.14 × (6 △ 2 △ 2) 2 × 2, = 36-3.14 × 2.25 × 2, = 36-14.13, = 21.87 (square decimeter); answer: the remaining sheet area is 21.87 square decimeter

Cut the largest square in the middle of a circular iron sheet with a diameter of 4dm. How many square meters is the square area? How many parts of the circular area is the waste?

What's your age? The next question is to explain this, the answer is to use what you can understand
The diagonal length of a square is the diameter of a circle
A square can be regarded as the area of two triangles and the diameter of a circle at the bottom of the triangle. The height is half of the diameter
Area of each triangle: = 4 * (4 / 2) / 2 = 4
Square as the sum of the area of two triangles = 4 * 2 = 8 (square DM)

The side length of a square is 8 decimeters. Draw the largest circle in it. How many parts of the square is the area of waste? (take 3 cm for π)

It can be seen from the title that the side length of the square is the largest, and the diameter of the circle is 8 decimeters
So the area of the circle is 16 π square decimeters
Because the square area is 64 square decimeters
So the waste area is 64-16 π
Then the area of the scrap is 64-16 π / 64 of the square area = 43 / 100
That is, the area of the waste occupies 43% of the area of the square

In the middle of a round piece of iron with a diameter of 8dm, cut the largest square. What is the area of the square? What is the proportion of the waste around the square?

Take the diameter of the circle as the diagonal to make a square with an area of 32. The area of the circle is 16 * 3.14, and the waste area is 16 * 3.14-32