a
n
g
l
e
o
f
d
i
f
f
r
a
c
t
e
d
r
a
y
(
0
t
o
π
/
2
)
0
.
5
w
a
v
e
l
e
n
g
t
h
(
0
.
0
1
r
t
o
r
)
7
.
1
9
1
3
d
i
s
t
a
n
c
e
d
b
e
t
w
e
e
n
s
l
i
t
s
1
5
.