Math Problem Statement

area of a land is 460 cm sq length is 15% more than it' breadth find the perimeter

Solution

Let the breadth of the land be denoted as bb, and the length as ll.

We are told that the length is 15% more than the breadth, which can be written as:

l=1.15bl = 1.15b

The area of the rectangle (land) is given as 460 cm². The formula for the area of a rectangle is:

Area=l×b\text{Area} = l \times b

Substituting l=1.15bl = 1.15b into this formula:

460=1.15b×b460 = 1.15b \times b

Simplifying:

460=1.15b2460 = 1.15b^2

To solve for bb, divide both sides of the equation by 1.15:

b2=4601.15b^2 = \frac{460}{1.15} b2=400b^2 = 400 b=400=20b = \sqrt{400} = 20

So, the breadth bb is 20 cm.

Now, using l=1.15bl = 1.15b, we can find the length:

l=1.15×20=23cml = 1.15 \times 20 = 23 \, \text{cm}

The perimeter of a rectangle is given by the formula:

Perimeter=2(l+b)\text{Perimeter} = 2(l + b)

Substituting the values for ll and bb:

Perimeter=2(23+20)=2×43=86cm\text{Perimeter} = 2(23 + 20) = 2 \times 43 = 86 \, \text{cm}

Therefore, the perimeter of the land is 86 cm.

Would you like more details on how this was calculated, or have any questions?

Here are some related questions for you:

  1. How would the perimeter change if the length were 25% more than the breadth?
  2. What is the area of a rectangle if the length is 30 cm and the breadth is 15 cm?
  3. How do you find the area and perimeter of a triangle?
  4. What would happen if the breadth was decreased by 10%?
  5. Can the same formula for area and perimeter apply to a circle?

Tip: When solving problems like this, always express relationships clearly first (like "15% more than") before applying the area formula.

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Math Problem Analysis

Mathematical Concepts

Geometry
Algebra
Percentage

Formulas

Area of a rectangle: Area = length × breadth
Perimeter of a rectangle: Perimeter = 2(length + breadth)
Percentage increase formula: New value = Original value × (1 + Percentage/100)

Theorems

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Suitable Grade Level

Grades 6-8