NCERT Solutions
Class 10 - Mathematics - Chapter 4: QUADRATIC EQUATIONS - Exercise 4.3
Question 3

Question. 3

Is it possible to design a rectangular mango grove whose length is twice its breadth, and the area is 800 m²? If so, find its length and breadth.

Answer:

Yes. Length = 40 m, Breadth = 20 m

Detailed Answer with Explanation:

Step 1: Define the variables.

Let the breadth of the rectangular mango grove be \(b\) metres.

Then, according to the question, the length is twice the breadth, so:

\[\text{Length} = 2b\]

Step 2: Use the area condition.

Area of a rectangle = length × breadth.

We are given that the area is 800 m². So:

\[\text{Area} = (\text{Length}) \times (\text{Breadth}) = 2b \times b = 800\]

That is,

\[2b^2 = 800\]

Step 3: Form and solve the equation.

Divide both sides by 2:

\[b^2 = 400\]

Take square roots of both sides:

\[b = \pm 20\]

Since breadth is a physical length, it must be positive, so:

\[b = 20\,\text{m}\]

Step 4: Find the length.

Length = \(2b = 2 \times 20 = 40\,\text{m}\).

Step 5: Check if the design is possible.

Check the area with these dimensions:

\[\text{Area} = 40 \times 20 = 800\,\text{m}^2\]

The condition is satisfied.

Conclusion: Yes, such a rectangular mango grove is possible. The breadth is 20 m and the length is 40 m.

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