If the perimeter of a rectangle is a & nbsp; cm, and the width ratio is 3 cm, the length of the long side of the rectangle is () A. （a+3）÷4B. （a+a×2）÷2C. （a÷2-3）÷2D. （a÷2+3）÷2

If the perimeter of a rectangle is a & nbsp; cm, and the width ratio is 3 cm, the length of the long side of the rectangle is () A. （a+3）÷4B. （a+a×2）÷2C. （a÷2-3）÷2D. （a÷2+3）÷2

(a △ 2 + 3) △ 2, so D

The circumference of a rectangle is 20 cm. Calculate the length and width

There are several ways
If the length is 7cm, the width is (20-2 * 7) / 2 = 3cm
The length is 6cm and the width is (20-2 * 6) / 2 = 4
The length is 8cm and the width is (20-2 * 8) / 2 = 2
wait

The circumference of a rectangle is 24 cm, and its length and width are in whole centimeters. How many different situations does this rectangle have?

Perimeter is 24 cm, then length + width = 24 / 2 = 12 cm
The length and width are in whole centimeters, and the length is greater than or equal to the width
6+6=12
7+5=12
8+4=12
9+3=12
10+2=12
11+1=12
There are six

The circumference of a rectangle is 24 cm, and its length is twice its width. What is the length and width of a rectangle
Oh, who knows?

∵ rectangular perimeter = (length + width) × 2
｜ length + width = 12
Length = 2 times width
Length + width = 3 times width
Ψ width = 12 △ 3 = 4, length = 4 × 2 = 8

The circumference of a rectangle is 30cm, and the length is 12cm. To find out the width, the equation is given

Set the width x cm,
（x+12）*2=30
The solution is x = 3
A: 3 cm wide

The circumference of a rectangle is 20 cm, and the length and width are the whole number of centimeters. When the length and width are respectively how many centimeters, the area of the rectangle is the largest?

When: length = width, the area is the largest
Length = width = 20 ﹣ 2 ﹣ 2 = 5cm
Area = 5 × 5 = 25 square centimeter

The perimeter of a rectangle is 48CM, the width is 3 / 5 of the length. What is the area of the rectangle

Let X be the width and y be the length
X＋Y＝48÷2＝24
∵ X∶Y＝3∶5
∴X＝3Y／5
∴3Y／5＋Y＝24
Y＝15
∴X＝9
9×15＝135
The area of this rectangle is 135 cm

The perimeter of a rectangle is 80 decimeters, its ratio of length to width is 4 to 1, and its area is () square decimeters

Length + width = 80 △ 2 = 40 decimeters
1+4=5
Length = 40x4 / 5 = 32
Width = 40x1 / 5 = 8
Area = 32x8 = 256 square decimeters

The perimeter of a rectangle is 80 decimeters, and the length is 6 decimeters more than the width. How many square decimeters is the area of this rectangle?

Width (80-6 * 2) / 4 = 17
Length 17 + 6 = 23
Area 23 * 17 = 391 square decimeters

The perimeter of the rectangle is 10 meters, the width is 23 meters, and the area of the rectangle is 10 meters______ Square meters

According to the circumference of the rectangle is 10 meters, we know: length + width = 10 △ 2 = 5 (meters); according to the width is 23 of the length, we know: width: length = 2:3; so width = 5 × 25 = 2 (meters); length = 5 × 35 = 3 (meters); s length = AB = 2 × 3 = 6 (square meters); so fill in: 6