Think of it like this :
Shaded area → 3 units = 9 cm²
1 unit = 9 cm² ÷ 3 = 3 cm²
Square area → 11 units
Since shaded area is ¼ of circle area,
Circle area = 3 units × 4 = 12 units
Area of figure = circle area + square area - shaded area(overlap)
= 12 units + 11 units - 3 units
= 20 units
= 20 × 3 cm²
= 60 cm²