An Important Question of M.L Aggarwal book of class 10 Based on Section Formula Chapter for ICSE BOARD.
The vertices of a triangle are given. Find the values asked if the centroid point of the triangle is given.
This is the Question Number 36, Exercise 11 of M.L Aggarwal.
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The vertices of a triangle are A ( – 5, 3), B (p, – 1) and C (6, q). Find the values of p and q if the centroid of the triangle ABC is the point (1, – 1).
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Given vertices of the triangle are A(-5,3), B(p,-1) and C(6,q).
Co-ordinates of centroid are (1,-1).
Co-ordinates of the centroid of a triangle, whose vertices are (x1,y1), (x2,y2) and (x3,y3) are
[(x1 + x2+ x3)/3, (y1 + y2+ y3)/3]
(x1,y1) = (-5,3)
(x2,y2) = (p,-1)
(x3,y3) = (6,q)
x co-ordinate of centroid, (x1 + x2+ x3)/3 = (-5+p+6)/3 = 1
p+1 = 3
p = 3-1
p = 2
y co-ordinate of centroid, (y1 + y2+ y3)/3 = (3-1+q)/3 = -1
2+q = 3×-1
2+q = -3
q = -3-2
q = -5
Hence the value of p and q are 2 and -5 respectively.