Question

Triangle PQR is the image of ABC under a dilation.
Find the coordinates of B and R. Find the ratio k/h.

Answer 1

Find scale factor
A-->P
(4,1) --> (7,7/4)
4*k = 7
1*k = 7/4
k=7/4
Apply scale factor to point C to find R
C-->R
(1,4) -->(1*k,4*k)
R=(7/4, 7)
To find B work backwards
B -->Q
(x,y) -->(x*k,y*k)
x*k = 21/4
x = (21/4)/k = 21/4 * 4/7 = 3
y*k = 35/4
y = (35/4)/k = 35/4 * 4/7 = 5
B = (3,5)

Ratio of k/h is same as scale factor k
= 7/4
all sides of larger triangle will be 7/4 X larger than smaller triangle

Answer 2

i got it and can u help me http://openstudy.com/groups/mathematics/updates/4dc9c0ca40ec8b0bc5a80d17