1. You must follow the rules of the zoo and the instructions of the staff of the zoo.
2. You must be calm and careful in the zoo.
3. You must pay attention to the zoo signs and labels.
4. You must be polite to other visitors.
5. You must keep the zoo tidy. You mustn't drop any litter there.
6. You mustn’t bring your pets to the zoo.
7. You mustn’t use flashlights when taking photos.
8. You mustn’t smoke at the zoo, bring your bicycles or use your rollers.
9. You mustn't feed or touch and pet animals. This is very dangerous!
10. You mustn't switch on music, make noise or shout in the zoo.
11. You mustn’t tease or scare animals or disturb them in any other way.
12. You mustn’t leave children unattended.
13. Do not go over the barriers and fencing. Строго запрещается заходить за ограждение.
14. You mustn’t break branches of trees and shrubs, pick up flowers and walk on the grass.
х=√6,76
3,4²=(5,8-3,9)²+х²
х²=11,56-3,61
х=√7,95