Hey There!
Answer:
I didn't quite get the question because there is no circle image but...
If 7.5 is the area of the circle, then:
Radius: 1.55
Diameter: 3.09
Explanation:
You can use the following formulas to help you:
To find radius: [tex]r=\frac{C}{2 \pi}\\[/tex] where r = radius and c = circumference
To find diameter: [tex]2 * r[/tex] where r=radius
Good Luck!