I was just browsing for unanswered posts and found this. So I thought about it, sorry it's been a long wait.
Not sure what you mean by 'triangle PQR ~ TUV'
See diagram below. Any answer is possible if the midpoint and ratio constraints are the only ones.
But if 'triangle PQR ~ TUV' means the triangles are similar then it becomes possible.
The areas of PQR and TUV will be in the ratio (3/5) squared.
As area of any triangle is half base x height, the line up from the midpoint will bisect the area (same height but base is half as long for each half).
So, if PQR : TUV = 9 : 25 then PSR : TUV = 4.5 : 25 = 9 : 50
hth
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