A triangle has corners at (7 ,8 ), (2 ,4 ), and (6 ,3 ). If the triangle is dilated by a factor of 2 about point #(6 ,12 ), how far will its centroid move?

1 Answer
Feb 10, 2018

Distance moved by centroid ~~ color(green)(20.25)

Explanation:

Centroid G ((7+2+6)/3,(8+4+3)/3)) => ((5),(5))

Dilation factor 2, dilated about D (6,12)

To find new coordinates of centroid G'

vec(G'D) = 2 * vec(GD)

G'((x-6),(y-12)) = 2 * ((5-6),(5-12)) => ((-2),(-14))

G'((5),(-1))

vec(GG') = sqrt((-2-5)^2 + (-14-5)^2) ~~ color(green)(20.25)