Question

Length and breadth of a rectangle are directly proportional if length from 6cm to 21cm and if breadth now is 14cm then what walls the breadth before any change in length occured

Answer 1

Answer:

4cm

Explanation:

Length and breadth of a rectangle = Directly proportional

Length of the rectangle (L1) = 6cm

Length of the rectangle (L2) = 21cm

Breadth of the rectangle = 14cm

Let the original b

readth be = x

Thus,

L1/B1 = L2/B2

Substituting the values -

= 6/x = 21/14

= 21x = 6 × 14

= 21x = 84

= x = 84/21

= x = 4

Therefore, the original breadth was 4cm

Answer 2

The breadth is 4 cm.

Given:

l1 = 6 cm; l2 = 21 cm; and b2 = 14 cm

Explanation:

We are given that the length and breadth are directly proportional.

So, we have:  

$\frac{l 1}{l 2}=\frac{b 1}{b 2} \rightarrow(1)$

Substituting these values in equation (1) we have:

$\frac{6}{21}=\frac{b 1}{14}$

Which can be further solved as:

$\frac{2}{7}=\frac{b 1}{14}$

Bringing all terms to one side we have:

$b 1=2 \times \frac{14}{7}$

That results in:

$b 1=2 \times 2$

or

b1 = 4 cm

Thus, the original breadth was 4 cm.