Answer: 963 cm²
Explanation:
We will find the area of the yellow rectangle and then subtract the portion that is missing.
A = LW
A = (36 cm)(39 cm)
A = 1,404 cm²
Missing portion's area.
A = LW
A = (21 cm)(21 cm)
A = 441 cm²
Subtracting.
1,404 cm² - 441 cm² = 963 cm²