Describe what is found at grid reference 48905094 in Fig. Using Fig 1.7 to identify the grid lines in Fig. 1.1, what is the grid reference for Ruswarp Police Office in Fig 1.1. This can only be done if there is an agreed 'baseline' to measure the height from. On Ordnance Survey maps this is known as the vertical datum and is the mean sea level at Newlyn in Cornwall.
Height is represented on maps in a number of ways.
In fact, such trig. Many maps also have contour lines, each of which joins up all the points at the same height. The closer together the contours are the steeper the slope is. With practice, by studying the contours on the map you can get a good picture in your mind of the general 3-dimensional landform. 1.8 SAQ 4.