A triangle has corners at (7 ,9 )(7,9), (1 ,7 )(1,7), and (6 ,2 )(6,2). How far is the triangle's centroid from the origin?

1 Answer
Jun 26, 2016

Triangle's centroid is 7.67.6 units away from the origin.

Explanation:

Centroid of a triangle, whose corners are (x_1,y_1)(x1,y1), (x_2,y_2)(x2,y2) and (x_3,y_3)(x3,y3), is given by (1/3(x_1+x_2+x_3),1/3(y_1+y_2+y_3))(13(x1+x2+x3),13(y1+y2+y3))

Hence centroid of the triangle whose corners are (7,9)(7,9), (1.7)(1.7) and (6,2)(6,2) is

(1/3(7+1+6),1/3(9+7+2))(13(7+1+6),13(9+7+2)) or (14/3,18/3)(143,183)

And its distance from origin (0,0)(0,0) is

sqrt((18/3-0)^2+(14/3-0)^2)=sqrt(324/9+196/9)(1830)2+(1430)2=3249+1969

= 1/3sqrt520=1/3xx22.8=7.613520=13×22.8=7.6