Label the vertices A (- 3, - 2), B (- 7, - 3 ), D (- 4, - 5 )
and the centre of dilatation C (- 7, - 6 ), then
CA = a - c = < - 3, - 2 > - < - 7, - 6 > = < 4, 4 >
CA' = 3 < 4, 4 > = < 12, 12 >
A' = (- 7 + 12, - 6 + 12 ) = ( 5, 6 )
CB = b - c = < - 7, - 3 > - < - 7, - 6 > = < 0, 3 >
CB' = 3 < 0, 3 > = < 0, 9 >
B' = (- 7 + 0, - 6 + 9 ) = (- 7, 3 )
CD = d - c = < - 4, - 5 > - < - 7, - 6 > = < 3, 1 >
CD' = 3 < 3, 1 > = < 9, 3 >
D' = (- 7 + 9, - 6 + 3 ) = ( 2, - 3 )
Summarising
(- 3, - 2 ) ⇒ (5 , 6 )
(- 7, - 3 ) ⇒ (- 7, 3 )
(- 4, - 5 ) ⇒ (2, - 3 )