In an equilateral triangle PQR , let the vertex P be at (3,5) and the side QR be along the line x+y=4. If the orthocentre of the triangle PQR is (α,β), then 9(α+β) is equal to :
(A)16
(B)27
(C)36
(D)48✓ Correct
Answer: (D)
Solution
The altitude from P(3,5) to the base QR:x+y=4 meets it at its midpoint M, found from 1x−3=1y−5=−12+123+5−4=−2, giving M=(1,3). In an equilateral triangle the orthocentre coincides with the centroid, which divides the median PM from the vertex in the ratio 2:1, so it is P+32(M−P)=(35,311). Hence 9(α+β)=9(35+311)=9⋅316=48.
JEE Main · 2026 · 05 Apr 2026 · Shift 1 · Single correct option