A triangle has corners at (2, 7 ), ( 5, -2), and ( 1, -5)#. If the triangle is reflected across the x-axis, what will its new centroid be?

1 Answer
Apr 20, 2016

Coordinates of new centroid are (7/3,0)

Explanation:

Reflection of a point (x,y) in x-axis is (x,-y).

Hence reflection of a triangle having corners at (2,7), (5,-2) and (1,-5) will be a triangle with corners at (2,-7), (5,2) and (1,5).

As coordinates of centroid of a triangle with points at (x_1,y_1), (x_2,y_2) and (x_3,y_3) is ((x_1+x_2+x_3)/3,(y_1+y_2+y_3)/3) and hence

Coordinates of new centroid are ((2+5+1)/3,(-7+2+5)/3) or (7/3,0)