0,0
A
B
C
x
y
z
v
xy
w
xy
p
xy
v
z
w
z
p
z
u
z
u
xy
az = 0.54
el = 0.44
0
D
E
F
G
H
I
J
x
y
z
\(\overline{v}\)
\(\overline{w}\)
\(\overline{v}\times\overline{w}\)
\(\overline{p}\)
\(\overline{q}\)