Let the three sides of a triangle are on the lines 4x−7y+10=0,x+y=5 and 7x+4y=15. Then the distance of its orthocentre from the orthocentre of the triangle formed by the lines x=0,y=0 and x+y=1 is
(A)5
(B)5✓ Correct
(C)20
(D)20
Answer: (B)
Solution
The lines 4x−7y+10=0 and 7x+4y=15 have slopes 74 and −47, whose product is −1, so the triangle is right-angled and its orthocentre is the right-angle vertex. Solving these two lines together gives x=1,y=2, so that orthocentre is (1,2). The triangle on x=0,y=0,x+y=1 is right-angled at the origin, so its orthocentre is (0,0). The distance between (1,2) and (0,0) is 1+4=5.
JEE Main · 2025 · 04 Apr 2025 · Shift 1 · Single correct option