Answer:
Correct answer is: A = 8 m π
Step-by-step explanation:
In fact, it is necessary to calculate the surface of the circular ring representing the circular window frame:
It's formula:
A = (R² - r²) π where R = m + 2 and r = m - 2
A = ((m + 2)² - (m - 2)²) π = (m + 2 + m - 2) (m + 2 - m +2) π = 2m · 4 π
A = 8 m π
God with you!!!