Explanation

Let's denote the length of the rectangle as L and the breadth as B.

According to the problem, the length exceeds the breadth by 4m, which can be expressed as L = B + 4.

The perimeter of a rectangle is calculated by adding the lengths of all its sides.

P = 2L + 2B.

We are given that the perimeter of the rectangle is 84m

2L + 2B = 84

Substituting L = B + 4 into the equation, we have:

2(B + 4) + 2B = 84

Simplifying the equation:

2B + 8 + 2B = 84

4B + 8 = 84

4B = 76

B = 19

Now, substitute the value of B back into L = B + 4:

L = 19 + 4

L = 23

Therefore, the length of the rectangle is 23m and the breadth is 19m.