A triangle has corners at (1, 2 ), ( 1 , -9), and ( 7, -1)#. If the triangle is reflected across the x-axis, what will its new centroid be?

1 Answer
Mar 11, 2016

New centroid is (3,8/3)

Explanation:

The centroid of the triangle with corners at (1,2), (1,-9) and (7, -1 ) is

((1+1+7)/3,(2+(-9)+(-1))/3) or (3,-8/3)

When triangle is reflected across the x-axis, its centroid too is reflected across the x-axis

and as reflection of a point (x_1,y_1) in x-axis is (x_1,-y_1),

new centroid is (3,8/3)