The length of the rectangle exceeds its breadth by 3 cm. If the length and breadth are each increased by 2 cm, then the area of new rectangle will be 70 sq. cm more than that of the given rectangle. Find the length and breadth of the given rectangle.
Answers
Concept:
A rectangle is a 2D shape having four sides and opposite sides are equal.
Given:
The length of the rectangle is 3 more than the breadth,
And,
If the length and breadth both increased by 2 cm, then the area of the new rectangle will be 70 sq. cm more than that of the given rectangle.
Find:
We are asked to find the length and breadth of the given rectangle.
Solution:
We have,
The length of the rectangle is 3 more than the breadth,
Now,
Let,
Breadth = a
So,
Length = 3 + a
Now,
Area of given rectangle = length × breadth = a × (3 + a) = 3a + a²
According to the question,
If the length and breadth both increased by 2 cm, then the area of the new rectangle will be 70 sq. cm more than that of the given rectangle.,
i.e.
Breadth = a + 2
So,
Length = 3 + a + 2 = 5 + a
Now,
Area of rectangle = 70 + Area of given rectangle
i.e.
(5 + a) × (a + 2) = 70 + 3a + a²
i.e.
5a + 10 + a² + 2a = 70 + 3a + a²
On solving we get,
4a = 70 - 4
i.e.
4a = 60
i.e.
a = 15 cm
i.e. Breadth = 15 cm
So,
Length = 15 + 3 = 18 cm
Hence, the length and breadth of the rectangle are 15 cm and 18 cm.
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