A line segment has endpoints at (3 ,2 )(3,2) and (2 , 4)(2,4). The line segment is dilated by a factor of 4 4 around (1 , 1)(1,1). What are the new endpoints and length of the line segment?

1 Answer
Mar 3, 2018

New endpoints color(red)(A’ (8,4), B’(4,12)

Length of the new line segment color(purple)(vec(A’B’) ~~ 8.9443

Explanation:

Given A (3,2), B (2,4) Rotated about C(1,1) by a factor of 4.

To find the new endpoints and the length of the line segment.

vec(A’C) = 4 * vec(AB)

a’((x),(y)) -=c((1),(1)) = 4 * ((3),(2)) - 4 * ((1),(1))

a’((x),(y)) = 4 * ((3),(2)) - 3 * ((1),(1)) = ((12),(8)) - ((4),(4)) = ((8),(4))

Similarly,

b’((x),(y)) = = 4 * ((2),(4)) - 3 * ((1),(1)) = ((8),(16)) - ((4),(4)) = ((4),(12))

Length of the new line segment

vec(A’B’) = sqrt((4-8)^2 + (4-12)^2) ~~ color (purple)(8.9443