\
Step 1:
\The polar curve is
.
The curve is a four leaved rose.
\Four loops of the rose are determined by substituting
.

General solution of sine function
is
.

Substitute
in above expression.

Arc length of the curve in polar form is
.
Consider
.
Differentiate with respect to
on each side.

Step 2:
\Substitute
,
and limits of
in the arc length formula.

Solution:
\Arc length of the polar curve
is
.