To find the area of the shaded portion, we need to subtract the area of the outer region from the area of the shaded region.

The area of the shaded region can be calculated by multiplying the breadth and length of the shaded region:

Area of shaded region = 4m * (1.5m + 1.5m) = 4m * 3m = 12m^2

The area of the outer region can be calculated by multiplying the breadth and length of the outer region:

Area of outer region = 12m * 18m = 216m^2

Therefore, the area of the shaded portion is:

Area of shaded portion = Area of shaded region - Area of outer region = 12m^2 - 216m^2 = -204m^2

Since the area cannot be negative, it seems that there may be an error in the given dimensions. Please double-check the values provided.