Area equals length times width
A=lw
Substitute what you know into the equation.
So, the area is 24 for each of them; substitute the different widths into the equation.
A=lw
24=l(1)
divide both sides by one to get 'l' alone.
l=24 cm
A=lw
24=l(2)
divide both sides by two to get 'l' alone.
l=12 cm
If you can solve it now, I can do more with you.