Length of painted cardboard = 8 cm and breadth of painted card = 5 cm
Since, there is a margin of 1.5 cm long from each of its side.
Therefore reduced length
= 8 – (1.5 + 1.5) = 8 – 3 = 5 cm
And reduced breadth
= 5 – (1.5 + 1.5) = 5 – 3 = 2 cm
Therefore Area of margin = Area of cardboard (ABCD) – Area of cardboard (EFGH)
= (AB x AD) – (EF x EH)
= (8 x 5) – (5 x 2)
= 40 – 10
= 30 cm2
Thus, the total area of margin is 30 cm2.