Perimeter=2L+2W, in this case L=80+2(25) and W=170+2(25) so
P=2(L+W)=2(80+50+170+50)
P=2(350)=700m
Parameterize
by

with
and
. Take a normal vector to
,

which has norm

Then the integral of
over
is


It is TRUE that a corollary is a statement that can be easily proved using a theorem.