Answer:
Scale factor is 2.5.
Explanation:
The triangles are drawn below.
From the triangle ΔABC,
AB = 2 units, BC = 2 units
From the triangle ΔA'B'C',
A'B' = 5 units, B'C' = 5 units.
Scale factor of a dilated figure is given as:
Scale factor =

Therefore, the scale factor is 2.5.