The number of equality parts is : 3 + 4 + 5 = 12 ( parts )
1 part = 144 : 12 = 12 ( m )
The smaller bottom is : 12 x 3 = 36 ( m )
The bigger bottom is : 12 x 4 = 48 ( m )
The height is : 12 x 5 = 60 ( m )
The area of the plot is : ( 36 + 48 ) x 60 = 5040 ( m2 )
Ans : 5040 m2
=3