The strategy that will best help Sadie understand her reading of August’s character is:
Sadie can make a mental picture of a boy with a scarred face and long hair.
This strategy directly relates to the context of the excerpt, as it encourages Sadie to visualize August's physical appearance and understand the impact of Julian's comments on him. By picturing August's face and hair, she can better grasp how he might feel about the remarks made by Julian, which is crucial for understanding his character and the dynamics in the story.