Question

What is the length of the radius of the circle?

Answer 1

The triangle is a right-angled triangle. note that the radius of the circle is also the 3rd side of the triangle which has no value.

To find the radius of the circle, just find the length of that 3rd side of that triangle.

Using Pythagoras Theorem,
10^2 = 8^2 + x^2 , where x is the length of the 3rd side.
100 = 64 + x^2
x^2 = 36
x= 6

Option 2 is the answer.