A 128 cm long iron wire is enclosed into a rectangle according to the ratio of length to width of 5:3. How many square centimeters is the area of the rectangle?

128 △ 2 = 64cm
5+3=8
The length is 64 × 5 / 8 = 40 cm
The width is 64 × 3 / 8 = 24 cm
The area of this rectangle is 40 × 24 = 960 square centimeters

The relationship between the area s (square of CM) of the rectangle and the length L (CM) of one side is
And draw function image, the most important thing is to draw pictures

S=L*(15-L)=15L-L*L
It's just a quadratic equation of one variable. You can draw it,

Fold a 34cm long iron wire into a rectangle with an area of 30cm ^ 2. How long is the diagonal of the rectangle?

The length is 15 and the width is 2
The diagonal can be found by Pythagorean theorem
That is 15 square plus 2 square,
229, root again

If the wire is used to form a 6-decimeter rectangle, how many square decimeters is the area of the rectangle?

Solution:
Suppose: the wire is a 6-decimeter rectangle, and the other is X
Perimeter: 4 * 5 = 20
2(X+6)=20
X=4
S rectangle = 4 * 6 = 24

Use a 16 decimeter long iron wire to form a circle, and the length of the joint is 0.3 decimeter. The area of this circle should be expressed in terms of square decimeter, which is best explained

Calculation perimeter: 16-0.3 = 15.7dm calculation radius: 15.7 △ 2 △ 3.14 = 2.5dm calculation area: 3.14 × 2.5 = 49.0625dm area is 49.0625m2

A square iron plate with a circumference of 24 decimeters, cut out the largest circle, and the area of the circle is______ Square decimeter (π = 3.14)

24 △ 4 = 6 (decimeter), 3.14 × (62) 2 = 28.26 (square decimeter). A: the area of this circle is 28.26 square decimeter

The circumference of a square piece of iron is 40 decimeters. What is the circumference of the largest circle cut from this piece of iron? What is the area of the circle? What is the area of the leftover material

The circumference of the largest circle = 10 π
Area = 5 & # 178; π = 25; area of π corner = 10 & # 178; × (1 - π / 4) = 100 × 0215 = 21,5 (DM & # 178;)

Use a piece of paper-cut 8 decimeters long and 6 decimeters wide to create the largest circle. The area () and perimeter () of the circle

Cut a 16 decimeter square paper into the largest circle. What is the area of the cut part

16 △ 4 = 4 decimeters, the side length of a square is also the diameter of a circle
Then the radius is: 4 △ 2 = 2 decimeters
The area of the cut part: 4 × 4-3.14 × 2 & # 178; = 3.44 square decimeters

If a square and a circle have the same area, what is their perimeter ratio

Let the side length of a square be a,
The radius of the circle is r
Then: A ^ 2 = Pai * R ^ 2
The ratio of perimeter is: A: r = radical Pai

A 128 cm long iron wire is enclosed into a rectangle according to the ratio of length to width of 5:3. How many square centimeters is the area of the rectangle?