Answer:
5.4
Explanation:
Notice that if you create a line that joins line 2.4 and line 9.6 you then form a right triangle with a hypotenuse equal to the radius. Then use the Pythagorean Theorem to solve for the radius:
(4.8^2)+(2.4^2)=C^2
23.04+5.76=C^2
28.8=C^2
√28.8=√C
5.4=C