If loops 2 and 4 of a logarithmic spiral are 8cm and 18cm from the center, then how far is loop 3 from center?

Answer 1

r = ae^bθ
18 = ae^8πb
8 = ae^4πb
4πb = ln(9/4)
b = 0.064531776206704092300507425000367
a = 32/9
ae^6πb = 12 cm