Answer: Length = 43 ; Breadth = 21.5
Explanation:
Let the width be 'x'
The length = 2x
The perimeter = 129
Formula of perimeter of rectangle = 2 ( length + breadth )
Substitute:
2 ( 2x + x ) = 129
2 ( 3x ) = 129
6x = 129
x = 21.5
Therefore, the width = 21.5
Length = 2x = 2(21.5) = 43