Answer:
A. 5.4 in
Explanation:
At the top of the line segment GH, you can see it ends on Circle D's circumference. Therefore, if you made a line segment from D to G, its length would be the radius. Lines DE and GH are perpendicular and make a 90 degree angle, so you can make line DG a hypotenuse, use pythagoreans theorem, and find the radius. However, since they intersect at a halfway point, you have to divide 10 and 4 by 2. 10/2 = 5 4/2 = 2 5^2 + 2^2 = r^2
5^2 = 25 and 2^2 = 4, so 29 = r^2. The square root of 29 is 5.385, or 5.4 inches.
I got a bit lazy answering this, but I hope it helps!