For a logarithmic spiral with parametric equations
(1)
 
(2)

the involute is given by
(3)
 
(4)

which is another logarithmic spiral scaled by a factor of and rotated by an angle .
For a logarithmic spiral with parametric equations
(1)
 
(2)

the involute is given by
(3)
 
(4)

which is another logarithmic spiral scaled by a factor of and rotated by an angle .
Weisstein, Eric W. "Logarithmic Spiral Involute." From MathWorldA Wolfram Web Resource. https://mathworld.wolfram.com/LogarithmicSpiralInvolute.html