Answer:
B
Step-by-step explanation:
under a dilatation about the origin of scale factor 3
since dilatation is about the origin multiply the coordinates of A, B and C by 3
A(8, 15) → A' (24, 45)
B(12, 13) → B'(36, 39)
C(8, 10) → C'(24, 30)
using the distance formula
with (x₁, y₁ ) = C'(24, 30) and (x₂, y₂ ) = B'(36, 39)
BC = [tex]\sqrt{(36-24)^2+(39-30)^2}[/tex]
= [tex]\sqrt{144+81}[/tex] = [tex]\sqrt{225}[/tex] = 15 → B
