The area of the above given figure can be calculated as:

(a) We know that,

Area of rectangle = Length × Breadth

Therefore,

Atrea of 1^st rectangle = 12 × 2 = 24 cm²

Also,

Area of 2^nd rectangle = 8 × 2 = 16 cm²

Thereore,

Total area= 24 + 16 cm²

= 40 cm²

(b) The area of the above given figure can be calculated as:

We know that,

Area of rectangle = Length × Breadth

Also,

Area of square = (Side)²

Therefore,

Area of 1^st rectangle = 21 × 7

= 147 cm²

Area of 2^nd square = 7 × 7

= 49 cm²

Also,

Area of 3^rd square = 7 × 7

= 49 cm²

Therefore,

Total Area = 147 + 49 + 49

= 245 cm²

(d) The area of the above given figure can be calculated as:

We know that,

Area of rectangle = Length × Breadth

Therefore,

Area of 1^st recatngle = 5 × 1 = 5 cm²

Also,

Area of 2^nd rectangle = 4 × 1 = 4 cm²

Therefore,

Total area = 5 + 4 = 9 cm²