A triangle has corners at #(0, 5 )#, ( 1, -2)#, and #(7, -4 )#. If the triangle is reflected across the x-axis, what will its new centroid be?

1 Answer
Name
Jan 16, 2016

#C=(2 2/3,-1/3)#

Explanation:

  • You can find the centroid of the triangle before it is reflected, and just reflect that point.

  • When you reflect a point across the x axis, you change the sign of the y-coordinate and leave the x-coordinate as it is.

  • You can find the centroid you can use the centroid formula:
    #"Centroid (C)"=((x_1+x_2+x_3)/3,(y_1+y_2+y_3)/3)# (TutorVista.com, 2016)

  • #C=((0+1+7)/3,(5-2-4)/3)#

#C=(2 2/3,-1/3)#

  • The reflection of that centroid is #(2 2/3,1/3)#

-References
TutorVista.com, 2016. Centroid Formula. [Online]. Available from:
http://formulas.tutorvista.com/math/centroid-formula.html. [Accessed: 16th Jan 2016].

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