Let a triangle be represented by PQR as it's three vertices. Let the (x , y) co-ordinates of vertices be given. Now circumcentre of triangle can be found out by following steps :-

• Consider any two sides of triangle. Suppose PQ and PR. 
• Now find the midpoint of PQ and PR by using the formula :- { (x1+x2)/2 , (y1+y2)/2 }
• After finding the midpoint calculate the slope of PQ and PR by using the formula :- { (y2-y1) /(x2-x1) }
• By using slope and the midpoint of PQ find the bisector equation by using the formula :-    (y-y1)  = m(x-x1).
• Similarly find out the other bisector equation of PR by (y-y1) = m(x-x1).
• Now solve the two bisector equations to find the x and y. 
• Calculated x and y will be the circumcentre of the triangle. 

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