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

1 Answer

New Endpoints are (-2, -1)(2,1) and (6, -5)(6,5)
Length l=8.94427" "l=8.94427

Explanation:

Let A(x_a, y_a)=(1, 2)A(xa,ya)=(1,2)
Let B(x_b, y_b)=(3, 1)B(xb,yb)=(3,1)
Let R(x_r, y_r)=(2, 3)R(xr,yr)=(2,3)

Let the new endpoints be
C(x_c, y_c)C(xc,yc) and D(x_d, y_d)D(xd,yd)

Let k=4k=4

Solve the new endpoints by ratio and proportion

(RC)/(RA)=kRCRA=k

(x_c-x_r)/(x_a-x_r)=4xcxrxaxr=4
(x_c-2)/(1-2)=4xc212=4

x_c=-2xc=2

(y_c-y_r)/(y_a-y_r)=4ycyryayr=4
(y_c-3)/(2-3)=4yc323=4

y_c=-1yc=1

(RD)/(RB)=kRDRB=k
(x_d-x_r)/(x_b-x_r)=4xdxrxbxr=4
(x_d-2)/(3-2)=4xd232=4
x_d=6xd=6

(y_d-y_r)/(y_b-y_r)=4ydyrybyr=4
(y_d-3)/(1-3)=4yd313=4
y_d=-5yd=5

Length

l=sqrt((x_d-x_c)^2+(y_d-y_c)^2)l=(xdxc)2+(ydyc)2
l=4sqrt(5)=8.94427" "l=45=8.94427

God bless....I hope the explanation is useful