yes on an unlocked devise it will work,but it will not run at&t apps such as the GPS service and at&t radio
no
I found some on Amazon.com, very cheap, only $4.99 There are many you can choose from. http://www.amazon.com/SAMSUNG-FOCUS-i917-GEL-CASE/dp/B0047K8SVM
http://i917.photobucket.com/albums/ad12/pittsburgh267/triangles.png Follow the above link to a diagram of the problem. Imagine the above diagram as two similar triangles, with the base of the smaller triangle being x and the height being 5.5, and the base of the larger triangle being 3+x and the height 12. Using proportions and cross multiplication given the similar triangles you can calculate the shadow length. 12/3+x = 5.5/x 12x=5.5 (3+x) 12x=16.5 + 5.5x 6.5x=16.5 x=2.538 feet