A line segment has endpoints at (1 ,6 )(1,6) and (5 ,8 )(5,8). The line segment is dilated by a factor of 4 4 around (2 ,1 )(2,1). What are the new endpoints and length of the line segment?

1 Answer
Feb 10, 2018

New end points A' ((-2),(21)), B'((14),(29))

Line segment length ~~ color(green)(28.64

Explanation:

Given : A(1,6), B(5,8), dilated around C(2,1), dilation factor 4

To find the end points of the line segment and its length

vec(A'C) = 4 * vec(AC) or a' = 4a - 3c

a' = 4((1),(6)) - 3 ((2),(1)) = ((4),(24)) - ((6),(3)) = color(brown)(((-2),(21))

vec(B'C) = 4 * vec(BC) or b' = 4b - 3c

b' = 4((5),(8)) - 3 ((2),(1)) = ((20),(32)) - ((6),(3)) = color(brown)( ((14),(29))

Length of the line segment using distance formula,

vec(A'B') = sqrt((-2-14)^2 + (3-29)^2) ~~ color(green)(28.64