Hight is measured from _________________.
Sea level
__________ __________ are lines that join places of the same hight.
Contour lines
True or false: there must always be a key for layer colouring.
True
What type of relief is shown as a black dot?
Spot heights
Spot heights use what to signify the highest point?
A triangular pillar
Layer colouring is usually used where?
Atlases