
Let ABCD be the rectangular field and KLMN and PQRS the two rectangular roads with width 1.8 m and 2.5 m, respectively.
Given that length of rectangular field = 50 m
Breadth of rectangular field = 40m
Area of rectangular field ABCD = 50 m x 40 m
= 2000 m2
Area of the road KLMN = 40 m x 2.5 m
= 100 m2
Area of the road PQRS = 50 m x 1.8 m
= 90 m2
Clearly area of EFGH is common to the two roads.
Thus, Area of EFGH = 2.5 m x 1.8 m = 4.5 m2
Hence, Area of the roads = Area of KLMN + Area of PQRS – Area of EFGH
= (100 m2 + 90 m2) – 4.5 m2
= 185.5 m2
Area of the remaining portion of the field = Area of the rectangular field ABCD – Area of the roads
= (2000 – 185.5) m2
= 1814.5 m2