A triangle has corners at (5 ,3 )(5,3), (4 ,6 )(4,6), and (8 ,5 )(8,5). If the triangle is dilated by a factor of 2 2 about point (3 ,2 )(3,2), how far will its centroid move?

1 Answer
Apr 18, 2018

(8sqrt2)/3823

Explanation:

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Let G(x_a,y_a)G(xa,ya) be the centroid of DeltaABC, as shown in the figure,
G(x_a,y_a)=((5+4+8)/3, (3+6+5)/3)=(17/3,14/3)
Let D(3,2) be the center of dilation.
Let d be the distance between D and G,
=> d=sqrt((17/3-3)^2+(14/3-2)^2)=(8sqrt2)/3 units
given that the scale factor k=2,
=> the centroid G will move by (k-1)xxd=(2-1)xx(8sqrt2)/3=(8sqrt2)/3 units