Prove Existence of 5 & 64 Points in Plane with 8 & 2005 Right-Angled Triangles

sachinism
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Prove that there exist

(a) 5 points in the plane so that among all the triangles with vertices among these points there are 8 right-angled ones;

(b) 64 points in the plane so that among all the triangles with vertices among these points there are at least 2005 right-angled ones.
 
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CRGreathouse said:
Source: Junior Balkan MO 2005

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thanks again
 

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