15.
Tom draws rectangles whose length are width are related. Lets say that given one of the sides, by multiplying this numer by a constant, we should get the other one. Let k be this constant . So, given a width of 2, we have a length of 3.6. An equation would be
So if we want to find the value of k, then
So, by knowing the width, we multiply this number by 1.8 to get the length. So for a rectangle of a with of 3.5, we get
So the length of the rectangle should be 6.3