A line segment has endpoints at (3 ,2 )(3,2) and (6 ,8 )(6,8). The line segment is dilated by a factor of 4 4 around (1 ,3 )(1,3). What are the new endpoints and length of the line segment?

1 Answer
Mar 19, 2017

The new end points are (9,-1)(9,1) and (21,23)(21,23)
The length of the line segment is =26.8=26.8

Explanation:

Let ABAB be the line segment

A=(3.2)A=(3.2)

B=(6,8)B=(6,8)

Let A'B' be the line segment after the dilatation X4

The center of dilatation is D=(1,3)

vec(DA')=4vec(DA)=4*<2,-1> = <8,-4>

A'=(8+1,-4+3)=(9,-1)

vec(DB')=4vec(DB)=4*<5,5> = <20,20>

B'=(20+1,20+3)=(21,23)

The length of the line segment

A'B'=sqrt((21-9)^2+(23+1)^2)

=sqrt(12^2+24^2)=26.8