Length of rectangular garden be ‘x’ m.

Breadth of rectangular garden be ‘y’ m, then

Length of the garden is 4m more than its width.

x = y + 4 ……….. (i)

x – y = 4

Half of the circumference is 36 m.

\(\frac{2x + 2y}{2}\) = 36

2x + 2y = 72

x + y = 36 …………… (ii)

∴ x – y = 4 (i)

x + y = 36 (ii)

From eqn. (i) + eqn. (ii)

∴ x = 20 m.

Substituting the value of ’x’ in eqn. (i)

x – y = 4

20 – y = 4

-y = 4 – 20

-y = -16

y = 16 m.

∴ Length of the garden = 20 m.

Breadth of the garden = 16 m.