4. Is positive 63
I think so
If the points are collinear, then that means they lie on the same line when connected to each other. In order to prove this, the distances between the points must sum up to the length of the line.
AB + BC = AC
7 + 4 ? 9
11 ≠ 9
Since they do not sum up, therefore, the points are not collinear.
Answer:15
Step-by-step explanation: this is an equilateral triangle and 45-15-15=15 so no matter what it would be 15