A rectangular iron plate 10 decimeters long and 8 decimeters wide, cut it into the largest circle, how much less than the original area?

A rectangular iron plate 10 decimeters long and 8 decimeters wide, cut it into the largest circle, how much less than the original area?

[10 × 8-3.14 × (8 △ 2) 2] / (10 × 8), = [80-50.24] / (80, = 29.76 △ 80, = 37.2%). A: the area is 37.2% less than the original

A rectangular board is 10 decimeters long and 8 decimeters wide. If you saw it into the largest circle, how much less is the area than the original rectangle?
Formula
Make the formula clear

The area of the circle is (8 / 2) ^ 2 * 3.14 = 50.24
Area of upper square: 10 * 8 = 80
The area is (80-50.24) / 80 * 100% = 37.2% less than that of the original rectangle

How many percent less is the area of a square iron plate 10 decimeters long and 8 decimeters wide cut into the largest circle?

The diameter of the largest circle after cutting should be 8 decimeters
1 - (∏*4*4)/(10*8)
=628 (Note: the value of Π is calculated as 3.14)
= 0.372
= 37.2 %

A rectangular iron plate 10 decimeters long and 8 decimeters wide, cut it into the largest circle, how much less than the original area?

[10 × 8-3.14 × (8 △ 2) 2] / (10 × 8), = [80-50.24] / (80, = 29.76 △ 80, = 37.2%). A: the area is 37.2% less than the original

If the length of a rectangular iron plate is 2.5 times of the width and the width is 2.5 × 10 square cm, the area of the rectangular iron plate is

If the length of a rectangular iron plate is 2.5 times of the width, and the width is 2.5 × 10 ﹥ 178; cm, the area of the rectangular iron plate is (15.625 m ﹥ 178;)
The width of rectangular iron plate is 2.5 × 10-178; cm is 2.5 M
Length of rectangular iron plate = 2.5m × 2.5m = 6.25m
The area of rectangular iron plate is 6.25 m × 2.5 m = 15.625 M;
Answer: the area of rectangular iron plate is 15.625 square meters

The area of a parallelogram is 10.88 square meters, and the bottom is 3.6 decimeters

10.88÷3.6 = 3.0222222.

The area of a parallelogram is 32.8 square meters. It is known that the bottom of a parallelogram is 8.2 meters. What is its height
To solve the equation

The area of a parallelogram is 32.8 square meters. It is known that the bottom of a parallelogram is 8.2 meters. What is its height
32.8 / 8.2 = 4 m

The area of a parallelogram iron plate is 14 square meters, and its height is 2.8 meters. If you cut it into the largest rectangle, its area will be reduced by 2.8 meters, so you can cut it into a rectangle

a b
c d
If it's a parallelogram like the above letter line, cut the line from point a down to CD, and from point d up to ab. after cutting, the bottom is 4m, the height is 2.8m, and the area is 11.2m2, 2.8m2 less than the original

After cutting off the two largest circles on a 4.5m long and 2m wide rectangular iron plate, how many square meters is the remaining iron plate area?

The diameter of the circle is 2 meters, and the remaining area is 4.5 * 2-2 * 3.14 * (2 / 2) & # 178; = 2.72 square meters

If the length of a rectangle is reduced by 2 decimeters, the area will be reduced by 18 square decimeters. At this time, it happens to be a square. What is the area of the original rectangle?

Let the side length of a square be x decimeter,
Then the width of the original rectangle is X minutes, the length is (x + 2) decimeters, and the area is x (x + 2) square decimeters,
According to the meaning of the title:
x(x+2)--x^2=18
The solution of this equation is as follows
　　　　x=9
x(x+2)=99
Answer: the area of the original rectangle is 99 square decimeters