You're in high school. You learned a long time ago that the distance between
any two points is . . .
square root of [ (difference in their x-values)² + (difference in their y-values)² ].
Your two points are (-9, 6) and (-3, 9).
The difference in their x-values is 6 .
The difference in their y-values is 3 .
The distance between the points is . . .
square root of [ (6)² + (3)² ] = √(36 + 9) = √45