A line segment has endpoints at (1 ,4 ) and (7 ,3 ). The line segment is dilated by a factor of 3 around (2 ,6 ). What are the new endpoints and length of the line segment?

1 Answer
Feb 20, 2018

New end points A’((-1),(0)), B’((17),(-3))

Length of line segment after dilation

vec(A’B’) = 16.2788

Explanation:

A (1,4), B (7,3), dilated around C (2,6) and dilation factor 3

A’ = 3A - 2C = 3((1),(4)) - 2((2),(6)) = ((3),(12)) - ((4),(12)) = ((-1),(0))

B’ = 3B - 2C = 3((7),(3)) - 2((2),(6)) = ((21),(9)) - ((4),(12)) = ((17),(-3))

Length of line segment after dilation

vec(A’B’) = sqrt((17+1)^2 + (-3-0)^2) = 16.2788