I assume each path
is oriented positively/counterclockwise.
(a) Parameterize
by

with
. Then the line element is

and the integral reduces to

The integrand is symmetric about
, so

Substitute
and
. Then we get

(b) Parameterize
by

with
. Then

and

Integrate by parts with



(c) Parameterize
by

with
. Then

and

2/5 of 50 is 20. 50-20=30. Making FG=30
We need a picture of the graph
I think the answer I d
but I am not good at math