Find the area enclosed by the figure (i) given below. All measurements are in centimeters.

From figure,

Area of shaded region = Area of square ABCD - Area of △EFG - Area of △HIJ ……..(1)

In △EFG and △HIJ,

FG = HI

IJ = EF

∠HIJ = ∠GFE (Both equal to 90°).

Hence, △EFG ≅ △HIJ by SAS axiom.

∴ Area of △EFG = Area of △HIJ.

Area of △EFG = $\dfrac{1}{2}$ × base × height

= $\dfrac{1}{2}$ × EF × FG

= $\dfrac{1}{2}$ × 5 × 6 = 15 cm².

Area of △HIJ = Area of △EFG = 15 cm²

Area of square ABCD = (side)² = (9)² = 81 cm².

Substituting values in (1) we get,

Area of shaded region = 81 - 15 - 15 = 51 cm².

Hence, area of shaded region = 51 cm².