Calculate the area of shaded region in Fig. 9.66, where all of the short line segments are at right angles to each other and 1 cm long.
As there are 9 short line segments along length and breadth of the large square,
Length of the large square = 9 × 1 = 9 cm
Breadth of the large square = 1 × 9 = 9 cm
There are 41 small squares of 1 cm × 1 cm each.
∴ Area of shaded region = Area of large square – Area of 41 small squares
= 9 × 9 – 41 × 1 × 1 = 81 – 41 = 40 cm2