A line segment has endpoints at (5 ,5 )(5,5) and (3 ,5 )(3,5). The line segment is dilated by a factor of 1/2 12 around (3 , 2)(3,2). What are the new endpoints and length of the line segment?

1 Answer
Jun 28, 2017

The new endpoints are (4,7/2)(4,72) and (3,7/2)(3,72) and the length of the line segment is =1=1

Explanation:

Let the line segment be ABAB

A=(5,5)A=(5,5) and

B=(3,5)B=(3,5)

C=(3,2)C=(3,2)

The length of the segment AB=2AB=2

Let point A'=(x,y) be the point after dilatation, then

vec(CA')=1/2 vec(CA)

((x-3),(y-2))=1/2((5-3),(5-2))=1/2((2),(3))

Therefore,

x-3=1, =>, x=4

y-2=3/2, =>, y=7/2

The point A'=(4,7/2)

Let point B'=(p,q) be the point after dilatation, then

vec(CB')=1/2 vec(CB)

((p-3),(q-2))=1/2((3-3),(5-2))=1/2((0),(3))

Therefore,

p-3=0, =>, p=3

q-2=3/2, =>, q=7/2

The point B'=(3,7/2)

The length of the segment A'B'=1