Step 1: The area of the rectangle = 20 cm × 12 cm = 240 cm². Step 2: The sum of the base lengths of the two shaded triangles is the length of the rectangle (20 cm). Step 3: Their height is the breadth of the rectangle (12 cm). Step 4: Total area of the 2 shaded triangles = 1/2 × sum of bases × height = 1/2 × 20 cm × 12 cm = 120 cm². Step 5: Area of the unshaded parts = Total area - Area of shaded triangles. Step 6: Area of unshaded parts = 240 cm² - 120 cm² = 120 cm². Answer: 120 cm²