Let the length of the shorter leg is x.
The length of the the longer leg will be (x+3) m.
The length of the hypotenuse will be (x+6) m.
Applying the pythagorus theorem,
Neglecting the negative value of x.
Length of the shorter leg: 9 cm
Length of the longer leg: 9+3 cm=12 cm
Length of hypotenuse: 9+6 cm= 15 cm.