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.