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
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].