D is the answer just took test
0.93 = 0.9
0.18 = 0.2
0.9 + 0.2 = 1.1
Answer 1.1
Given:
The equation is:

To find:
The solution for the given equation.
Solution:
We have,

It can be written as:



Taking square root on both sides, we get
[Radius cannot be negative]


Therefore, the value of r is about 6.36 cm.