(a) We know that,

Area of rectangle = Length × Breadth

Therefore,

Therefore, we complete the figure as shown below to find the area:

Area of 1^st rectangle = 4 × 2 = 8 cm²

Area of 2^nd rectangle = 6 × 1 = 6 cm²

Area of 3^rd rectangle = 3 × 2 = 6 cm²

Area of 4^th rectangle = 4 × 2 = 8 cm²

Hence,

Total Area = 8 + 6 + 6 + 8

= 28 cm²

(b) We know that,

Area of rectangle = Length × Breadth

Therefore,

Area of 1^st rectangle = 3 × 1 = 3 cm²

Area of 2^nd rectangle = 3 × 1 = 3 cm²

Area of 3^rd rectangle = 3 × 1 = 3 cm²

Hence,

Total Area = 3 + 3 + 3

= 9 cm²