Rectangle (11, 3)
Equations:
A
=
b h
b h
2
--------- -
J
=
b
12
Example:
Given: b=4_chain, h=7_rd, d=39.26_in. Set guesses for I, J, and Id in km^4.
Solution: A=28328108.2691_cm^2, P=23134.3662_cm, I=2.9257E–7_km^4, J=1.8211E–6_km^4,
Id=2.9539E–7_km^4.
Regular Polygon (11, 4)
Equations:
1
2
- - - n L
4
- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
A
=
180
⎛
⎞
T A N
- - - - - - - - -
⎝
⎠
n
L
- - -
2
- - - - - - - - - - - - - - - - - - - - - - - - - - -
r v
=
⎛
180
⎞
S I N
- - - - - - - - -
⎝
⎠
n
Example:
Given: n=8, L= 0.5_yd.
Solution: A=10092.9501_cm^2, P=365.7600_cm, rs=55.1889_cm, rv=59.7361, =135_°, =45_°.
P
=
2 b
+
2
h
I
=
2
2
+
h
Id
=
I
+
A
d
---------------------------- -
P
=
n L
rs
=
TAN
n 2
–
- - - - - - - - - - - - 180
=
n
3
b h
------------ -
12
L
-- -
2
180
⎛
⎞
-------- -
⎝
⎠
n
360
-------- -
=
n
Equation Reference 5-45