Geometryhard · Past Paper

The points (a, b+c), (b, c+a), and (c, a+b) are:

AVertices of a triangle
BCollinear
CConcyclic
DNone of these

✓ Correct Answer: B — Collinear

Area calculation: 0.5 |a(c+a-a-b) + b(a+b-b-c) + c(b+c-c-a)| = 0.5 |a(c-b) + b(a-c) + c(b-a)| = 0.5 |ac-ab+ba-bc+cb-ca| = 0. Thus collinear.

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