.
=
It is what you are given, according to the condition.
Simplify:
= ,
= .
Thus you have this quadratic equation for the RATIO .
You can solve the equation and find this ratio from there.
Notice that the ratio is THE ONLY thing which you can obtain from the given data,
and you can not obtain dimensions separately, because there is NO sufficient data for it.
To get better understanding of this fact, imagine two geometrically similar configurations.
The "ratio correlations" will be the same, but the real/actual dimensions will be different.
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For similar problems, see the lesson
- Problems on the area and the dimensions of a rectangle surrounded by a strip
in this site.