Answer:
Two figures are similar if they have the same shape:
For example, two rectangles are similar if the quotient between length and wide is the same.
Now, we know that one of the rectangles is 6cm by 4cm.
The quotient of the lengths is 6cm/4cm = 3/2
Here we have a problem; you wrote
" Another rectangle with adjacent
sides o on and x cm ....."
I guess that this means:
The other triangle has one side with a measure of x cm, and the other side will have the lenght A, a constant number that you can complete after.
Now, if this new triangle is similar to the first one, then we must have;
If x > A.
x/A = 6cm/4cm = 3/2
x = (3/2)*A.
if x < A
A/x = 6cm/4cm = 3/2
x = (2/3)*A
There you have the two possible values of x, for a known A.