A triangle has corners at #(1, 2 )#, ( 6, 7)#, and #( 4, -5)#. If the triangle is reflected across the x-axis, what will its new centroid be?
1 Answer
Feb 11, 2017
Explanation:
Before we can find the 'new' centroid we must find the existing one.
The coordinates of the centroid are the
#color(blue)"average"# of the x and y coordinates of the 3 vertices.
#rArrx_("centroid")=1/3(1+6+4)=11/3#
#rArry_("centroid")=1/3(2+7-5)=4/3#
#"coordinates of centroid "=(11/3,4/3)# Under a reflection in the x-axis.
#"a point "(x,y)to(x,-y)#
#rArr"new centroid "=(11/3,-4/3)#
