A line segment has endpoints at (1 ,4 )(1,4) and (7 ,9 )(7,9). The line segment is dilated by a factor of 3 3 around (2 ,6 )(2,6). What are the new endpoints and length of the line segment?

1 Answer
Jun 19, 2018

color(brown)(bar(A'B') = sqrt((-1-17)^2 + (0-15)^2) = 23.43

Explanation:

A (1,4), B (7,9), C (2,6), " dilation factor " 3

A'C = 3 (a - c), A' - c = 3a - 2c

A'((x),(y)) = 3((1),(4)) - 2((2),(6)) = ((-1),(0))

B'C = 3 (b - c), B' - c = 3b - 2c

B'((x),(y)) = 3((7),(9)) - 2((2),(6)) = ((17),(15))

Length of the line segment

color(brown)(bar(A'B') = sqrt((-1-17)^2 + (0-15)^2) = 23.43