A triangle has corners at (8,3), ( 5, -8),and(7, -4 )#. If the triangle is reflected across the x-axis, what will its new centroid be?

1 Answer
Oct 23, 2016

(203,3)

Explanation:

The first step is to find the coordinates of the centroid, (xc,yc)

Given that the vertices of a triangle are (x1,y1),(x2,y2),(x3,y3)

Then.

xc=13(x1+x2+x3) the average of the x-coordinates

and yc=13(y1+y2+y3) the average of the y-coordinates

Here.

(x1,y1)=(8,3),(x2,y2)=(5,8),(x3,y3)=(7,4)

xc=13(8+5+7)=203

and yc=13(384)=3

coordinates of centroid =(203,3)

Under reflection in the x-axis, a point (x ,y) → (x ,-y)

(203,3)(203,3)