Apparatus
1
contentum
A
rectangulum contentum
S
2
ante
penes
del.
producatur
A
3
bzdt
A
bzd
S
4
t
A
d
S
5
A
rectangulum
S
6
est
A
erit
S
7
azt
A
azd
S
8
A
rectangulum
S
9
azt
A
ad triangulum
azd
S
10
azt
A
azd
S
11
A
rectangulum
S
A rectangulum S 
azt A ad triangulum azd S