A triangle has corners at (1, 3 ), ( 8, -4), and (1, -5 )#. If the triangle is reflected across the x-axis, what will its new centroid be?

1 Answer
Mar 20, 2016

New centroid will be (10/3,2).

Explanation:

When a point (x,y) is reflected across x-axis, new point becomes (x,-y).

Hence corners of new triangle will be (1,-3), (8,4) and (1,5).

As centroid of a triangle with sides (x_1,y_1), (x_2,y_2) and (x_3,y_3) is given by ((x_1+x_2+x_3)/3,(y_1+y_2+y_3)/3)

New centroid will be ((1+8+1)/3,(-3+4+5)/3) or (10/3,2).