Try to work with the helping elements before looking at the solution…

Helping elements

• the 2 methods should be added in Tree, they will be inherited and available in SpatializedTree

• These 2 methods rely on existing instance variables, so no new instance variable is needed

• to avoid an integer division in getCrownBaseHeight(), make sure to write 2d / 3d (if the 2 operands of a division are integers, only the integer part is kept in the result: 2 / 3 = 1, but 2d / 3d = 1.5)

• adapt toString () in Tree to display the crownRadius and crownBaseHeight values

• use NumberFormat to display 1.12 instead of 1.119999999999, see the online javadoc for NumberFormat, try to have the english . decimal separator

A possible solution