We have a base 2 with an exponent power raised to -3
so in order to have a positive exponent factor, we take reciprocal of the number1/2^3.
now that the base has a positive exponent number, we simply multiply it the times on the exponent number, so: 1/2*2*2 = 1/8
hope this help
The diameter is the radius ×2
if the picture was bigger i would be able to help could u get it a bit bigger