The diagram shows a dilation of line AB about the origin O. Determine the scale factor of the dilation by following these steps.

✓ 1. Measure these lengths:
OA  = units
OA' = units

✓ 2. Measure these lengths:
OB  = units
OB' = units

✓ 3. Measure these lengths:
AB  = units
A'B' = units

✓ 4. Calculate this ratio: OA' / OA = 1.0 1.2 1.5

✓ 5. Calculate this ratio: OB' / OB = 1.0 1.2 1.5

✓ 6. Calculate this ratio: A'B' / AB = 1.0 1.2 1.5