The equation is
.
Definition of the arc length:
\If the curve
,
, then the length of the curve is defined as,
.
Find
.
Consider
.
Apply derivative on each side with respect to
.





.
Let length of curve in first quadrant is
then total length of the curve will be
.
Arc length of the curve
:
Substitute
and
in
.
The total arc length of the astroid is
.



Substitute
.









.
units.
units.