we are given scale of 2 units.
on graph paper the space is 2.5 cm.
length of glass = 8 units.
8 units = 2 units +2 units +2 units +2 units.
each 2 unit is = 2.5cm.
therefore,
8 units = 2 units +2 units +2 units +2 units = 2.5+2.5+2.5+2.5= 10cm.
therefore, the height of the the actual glass in cm is 10 cm.