Find the coordinates of the circumcenter of triangle whose vertices are A (5, -1), B (-1, 5) and C (6, 6).
As we learnt
Circumcircle: A circle circumscribing a triangle.
Let P (x, y) be the circumcentre of the triangle ABC
So, PA = PB = PC (As all of these equal the radius of the circumcircle)
⇒ PA2 = PB2 = PC2
Using PA2 = PB2
⇒ (x - 5)2 + (y + 1)2 = (x + 1)2 + (y - 5)2
⇒ x2- 10x + 25 + y2 + 2y + 1 = x2 + 2x + 1 + y2- 10y + 25
⇒ x - y = 0 … (1)
Now using PB2 = PC2
(x + 1)2 + (y - 5)2 = (x - 6)2 + (y - 6)2
⇒ 7x + y - 23 = 0. … (2)
From (1) and (2), we get
Hence the coordinates of the circumcentre are
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