I have new question for you today... if u ready, lets begin
we have two triangles, the main one is the blue the secondary is the red.
if we divide the main triangle into two triangles we will get
The red triangle a=1.25, b=4.5 and c=4.67
The new triangle will be a=100-1.25=98.75, 25-4.5=20.5 so c=sqrt((98.75)^2+(20.5)^2) ===> c=100.85
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Now we have two triangles
1- a=1.25, b=4.5 and c=4.67
2- a=98.75, b=20.5 and c=100.85
The question is there is some thing missing because when we want to combine the two triangles again suppose we get same length's of the the main triangles ( blue triangles ).
Even if you swap over the 1.25 and 4.5 the numbers don't add up. Where did you get this 'problem' from? And what actually is the question?
Also, subtracting the lengths of the sides doesn't give you a triangle - it gives you the shape left when you subtract one triangle from another (a trapezium).
Both side length number sets are describing right-angled triangles, complying with the pythagorean theorem. But they are not similar, having different angles and can't be drawn into one another as you did.
Because both triangles aren't similar, the triangles created by adding or subtracting the sides are no longer right-angled.