s
t
r
i
p
1
p
o
s
i
t
i
o
n
-
1
s
t
r
i
p
2
p
o
s
i
t
i
o
n
1
t
h
i
c
k
n
e
s
s
0
.
5
s
u
r
f
a
c
e
a
r
e
a
=
b
∫
a
2
π
y
1
+
2
d
y
d
x
x
s
t
r
i
p
1
s
t
r
i
p
2
a
1
=
-
1
a
2
=
1
b
1
=
-
0
.
5
0
0
b
2
=
1
.
5
0
0
s
u
r
f
a
c
e
a
r
e
a
=
1
2
.
5
6
6
4
s
u
r
f
a
c
e
a
r
e
a
=
1
2
.
5
6
6
4