### BARS::Pi and Phi 7th St. Exit on I-17 North in Phoenix, Arizona

This road sign was found at the 7th St. Exit of northbound I-17 in Phoenix, Arizona.

The road sign says...

```   +--------------------+
| 7th St         1/4 |
| Central Ave        |
| 7th Ave      1 1/4 |
| 19th Ave     2 1/4 |
+--------------------+
```
```   the numbers are:  7  (1/4)  7  (1 1/4)  19  (2 1/4)

the Phi math is:
(sqrt(19 - 7 - 7) + ((2 1/4) - (1 1/4))) * sqrt(1/4) = Phi

observe...
sqrt(19 - 7 - 7) = sqrt(5)
2 1/4 - 1 1/4 = 1
sqrt(1/4) = 1/2
(sqrt(5) + 1) * 1/2 = Phi = 1.61803399+

the Pi math is:
(19 + 7 - (sqrt(1/4) + (1 1/4) + (2 1/4))) / 7 = Pi (3.14)

observe...
sqrt(1/4) = 1/2
1/2 + 1 1/4 + 2 1/4 = 4
19 + 7 - 4 = 22
22/7 approximates Pi truncated to 2 decimal digits
```
##### Update::2008.05.22

A similar, yet different, road sign was seen on westbound I-10 in Phoenix.

The following road sign/highway evaluation was discovered while updating this BARS.

```   again, the numbers are:  7  (1/4)  7  (1 1/4)  19  (2 1/4)

rsHwyEval:  19 + 7 - 7 - sqrt((2 1/4) + (1 1/4) + sqrt(1/4)) = 17
* the road sign is on I-17
```

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 29 April 2007