一个长 250 m，宽 20 m 的操场要用铁丝网围起来，然后找出需要多少铁丝

矩形是由四个边组成的二维几何图形，其中相对的两个边相等且彼此平行。矩形的所有角都等价于直角。

矩形的属性

• 一个长方形的对边相等。
• 对角线相等。
• 一个长方形的四个角都相等。
• 矩形的对角线平分它的角。

矩形的周长

矩形的周长称为包围几何图形的边界的总长度。

矩形的周长 = 矩形所有边的总和

让我们假设 l 是矩形的长度，w 是其对应的宽度。

因为，我们知道，矩形的对边相等。

矩形的周长 = l + w + l + w

= 2l + 2w

= 2(l + w)

一个长 250 m，宽 20 m 的操场要用铁丝围起来，然后找出需要多少铁丝。

解决方案：

A playground that is 250 m long and 20 m broad can be considered as a rectangle. The wire needed to fence the playground implies covering the boundaries of the playground with wire.

Let us assume the perimeter of rectangle to be given by P. 

Now, we have, 

l = 250 m

w = 20 m 

According to the formula, we have, 

P =  2(l + w)

Substituting the values, we get, 

P = 2(250 + 20)

= 2 (270)

= 540 m 

Therefore, the total wire required to fence the playground is equivalent to 540 m. 

示例问题

问题 1：找到一个长 500 米、宽 100 米的矩形体育场围栏所需的铁丝？

解决方案：

Here we need to find the wire needed for fencing the rectangular stadium.

To find the wire needed for fencing we need to find the perimeter of the stadium.

As we know that

Perimeter of rectangle = 2 × (Length + Breadth)

Given :  

Length = 500 m

Breadth = 100 m

Perimeter of rectangle = 2 × (500 + 100)

Perimeter of rectangle = 2 × 600

Perimeter of rectangle = 1200 m

Wire needed for fencing the stadium will be 1200 m.

问题 2：计算哪个地面需要更多的电线用于围栏；边长为 150 m 的正方形地面还是长 150 m 和宽 50 m 的矩形地面？

解决方案：

Here we need to find which ground will require more wire

To find the wire needed for fencing we need to find the perimeter of both the ground.

As we know that

Perimeter of rectangle = 2 × (Length + Breadth)

Given :  

Length = 150 m

Breadth = 50 m

Perimeter of rectangular ground = 2 × (150 + 50)

Perimeter of rectangular ground = 2 × 200

Perimeter of rectangular ground = 400 m

Perimeter of square = 4 × Side

Given : Side = 150 m

Perimeter of square ground = 4 × 150

Perimeter of square ground= 600 m

Therefore,

Perimeter of square ground > Perimeter of rectangular ground.

Thus, 

Square ground will require more wire than Rectangular ground.

问题 3：以每米 50 卢比的价格计算长 100 m、宽 50 m 的矩形地块的围栏成本？

解决方案：

Here we need of find the cost of fencing a rectangular plot

As we know that

Perimeter of rectangle = 2 × (Length + Breadth)

Given:

Length = 100 m

Breadth = 50 m

Perimeter of rectangle plot = 2 × (100 + 50)

Perimeter of rectangle = 2 × 150

Perimeter of rectangle = 300 m

To find cost of fencing multiply cost of fencing by perimeter 

Cost of fencing = ₹50 × 300

Cost of fencing = ₹15000.

Therefore,

Cost of fencing the rectangular plot is ₹15000.

问题 4：以每平方米 100 卢比的成本计算长 50 m、宽 25 m 的矩形瑜伽场地的铺设成本² ？

解决方案：

Here we have to find the cost of carpeting the yoga ground

To find the cost of yoga ground we need to multiply the cost of per m² to the area of the ground.

Area of rectangle = Length × Breadth

Given :

Length = 50 m

Breadth = 25 m

Area of rectangular yoga ground = 50 × 25

Area of rectangular yoga ground = 1250 m²

Now,

Find the cost of carpeting

Cost of carpeting = ₹100 × 1250

Cost of carpeting = ₹125000

Therefore,

Cost of carpeting the yoga ground is ₹125000.