A line segment has endpoints at (7 ,6 )(7,6) and (5 ,2 )(5,2). The line segment is dilated by a factor of 4 4 around (4 ,3 )(4,3). What are the new endpoints and length of the line segment?

1 Answer
May 12, 2017

The new end points are (16.15)(16.15) and (8,-1)(8,1)
The length of the new segment is =sqrt320=17.9=320=17.9

Explanation:

Let the endpoints of the segment be AA and BB

A=(7,6)A=(7,6)

B=(5,2)B=(5,2)

Let the endpoints after dilatation be A' and B'

Let the point C=(4,3)

Then,

vec(CA')=4vec(CA)=4*<7-4,6-3> = <12,12>

A'=(12,12)+(4,3)=(16,15)

Similarly,

vec(CB')=4vec(CB)=4*<5-4,2-3> = <4,-4>

B'=(4,-4)+(4,3)=(8,-1)

The length of the segment A'B' is

=sqrt((16-8)^2+(15+1)^2)

=sqrt(64+256)

=sqrt320