let

l = the length of the rectangle

w = the width of the rectangle

A = 14 m^2 the area

the length of a rectangle is 3 m less than the width:

l = w - 3

A = l*w

l*w = 14

plug l = w - 3 into the last equation:

(w - 3)w = 14

by solving we find:

w = 5.53 m

click here to see the step by step solution of the equation:

l = w - 3

l = 5.53 - 3

l = 2.53 m

the dimensions are: the length is 2.53 m and the width is 5.53 m.