If a vertex of an equilateral triangle is the origin and the side opposite to it has the equation x + y = 1 then the orthocentre of the triangle is
13,13
23,23
None of these
Clearly orthocentre ' H ' lies on the line x−y=0
Now distance of O(0,0) from the line x+y−1=0 is 12 .
Centroid divides median in the ratio 2:1 ∴OH=23⋅12=23 (since triangle is equilateral, centroid coincides with orthocentre)
∴ orthocentre ≡23,23