1. Why are these structures solid? They have several solid (hard) bases. The bases are stable. The bases are firmly planted. There are many bases. Knowledge: principles connected to group figures in pairs Source des images : http://www.google.ca/search Wikimedia Commons/Newton2 Wikimedia Commons/Patrick Clenet Wikim edia Commons/Blanchardb Ministère de l’Éducation, du Loisir et du Sport Physical Education and Health, Second Year of Elementary School 1

2. They have several solid (hard) bases. Ministère de l’Éducation, du Loisir et du Sport Physical Education and Health Second Year of Elementary School Wikimedia Commons/Patrick Clenet 2

3. The bases are stable. Wikimedia Commons/Blanchardb Ministère de l’Éducation, du Loisir et du Sport Physical Education and Health, Second Year of Elementary School 3

4. There are many bases. Wikimedia Commons/Patrick Clenet Ministère de l’Éducation, du Loisir et du Sport Physical Education and Health, Second Year of Elementary School 4

5. The bases are firmly planted. Ministère de l’Éducation, du Loisir et du Sport Physical Education and Health, Second Year of Elementary School Wikimedia Commons/Patrick Clenet 5