The breadth is x.
The length is 2 m more than twice the breadth, so it's 2x+2.
The perimeter of a rectangle is twice the sum of the length and the breadth. The perimeter is 154 m.
[tex]2(x+2x+2)=154 \\
x+2x+2=\frac{154}{2} \\
3x+2=77 \\
3x=77-2 \\
3x=75 \\
x=\frac{75}{3} \\
x=25 \Leftarrow \hbox{the breadth} \\ \\
\hbox{the length:} \\
2x+2=2 \times 25+2=50+2=52[/tex]
The length of the swimming pool is 52 m, the breadth is 25 m.