Handy Facts - Dimensions & Space
Accuracy (Precision) of Latitude & Longitude measurements
The circumference of the earth is 24,901 miles or 40,072 m. Using the equator
as the worst case (because the lines of longitude get closer together away
from the equator and the lines of latitude are parallel, the precision of latitude
is best at the equator and the precision of longitude is the same everywhere),
you can calculate that one degree is 111 km or 69.2 miles.
One decimal point in a degree measure (eg, 45.4°)
gives you accuracy to 11 km or nearly 7 miles.
Put another way, that is a precision of plus or minus 5.5 km or 3.5 miles.
Six decimal points (eg, 34.123456°) is accurate to plus or minus 2
inches. Here's a handy table:
Decimal
Digits | Example | Precision |
|---|
| 0 | 43° |
± 34.6 miles |
| 1 |
43.1° |
± 3.46 miles |
| 2 |
43.12° |
± 609 yards |
| 3 |
43.123° |
± 61 yards |
| 4 |
43.1234° |
± 18.3 feet |
| 5 |
43.12345° |
± 22 inches |
| 6 |
43.123456° |
± 2 inches |
| 7 |
43.1234567° |
± 0.2 inch |
Estimating or Visualizing Floor Space (handy for apartments)
1000 - about 32 x 32 square, or 20 x 50
1200 - about 35.5 x 35.5 square, or 25 x 48, 20 x 60
1500 - about 39 x 39 square, or 20 x 75, 25 x 52
1750 - about 42 x 42 square, or 25 x 70
2000 - about 45 x 45 square, or 25 x 80, 30 x 67
2500 - 50 x 50 square, 30 x 83 3000 - about 55 x 55, or 25 x 120
Using common objects for measurements
| Object | Size |
|---|
| Business Card | 3 1/2" × 2" |
| Floor tile |
12" × 12" |
| US Quarter |
1 " |
| US penny |
3/4 " |
| Credit card |
3 3/8" × 2 1/8" |
US Coin Dimensions
|
Denomination
|
Cent
|
Nickel
|
Dime
|
Quarter
|
Half Dollar
|
Dollar
|
Golden Dollar
|
|
Composition
|
Copper Plated Zinc
2.5% Cu
Balance Zn
|
Cupro-Nickel
25% Ni
Balance Cu
|
Cupro-Nickel
8.33% Ni
Balance Cu
|
Cupro-Nickel
8.33% Ni
Balance Cu
|
Cupro-Nickel
8.33% Ni
Balance Cu
|
Cupro-Nickel
12.5% Ni
Balance Cu
|
Manganese-Brass
88.5% Cu
6% Zn
3.5% Mn
2% Ni
|
|
Weight
|
2.500 g
|
5.000 g
|
2.268 g
|
5.670 g
|
11.340 g
|
8.1 g
|
8.1 g
|
|
Diameter
|
0.750 in.
19.05 mm
|
0.835 in.
21.21 mm
|
0.705 in.
17.91 mm
|
0.955 in.
24.26 mm
|
1.205 in.
30.61 mm
|
1.04 in.
26.50 mm
|
1.043 in.
26.5 mm
|
|
Thickness
|
1.55 mm
|
1.95 mm
|
1.35 mm
|
1.75 mm
|
2.15 mm
|
2.00mm
|
2.00 mm
|
|
Edge
|
Plain
|
Plain
|
Reeded
|
Reeded
|
Reeded
|
Reeded
|
Plain
|
|
No. of Reeds
|
N/A
|
N/A
|
118
|
119
|
150
|
133
|
N/A
|
|