Answer:
a. 10
Explanation:
x is the radius and any line drawn from centre of the circle to the ends of circle is radius.
using pythagoras theorem:
base^2+height^2= Hypotenuse^2 (over here hypotenuse is radius)
6^2+8^2=x^2
36+64=x^2
100=x^2
x= root of(100)
x=10