Which of the following represents the correct formula for calculating the amount of fabric needed to make a curtain?

A. length x width) + seam allowance
B. (length x seam allowance) + width
C. (length + seam allowance) x (width + seam allowance)
D.(seam allowance x 2) + (length x width)

Which of the following represents the correct formula for calculating the amount of fabric needed to make a curtain?

Answer: (length + seam allowance) x (width + seam allowance)

The correct formula for calculating the amount of fabric needed to make a curtain is (C) (length + seam allowance) x (width + seam allowance).

To determine the amount of fabric needed to make a curtain, you will need to consider the dimensions of the curtain itself as well as any additional requirements, such as seam allowance.

In option A, the formula is (length x width) + seam allowance. This option calculates the area of the curtain (length x width) and then adds the seam allowance. This formula is incorrect because the seam allowance should be accounted for in both length and width.

In option B, the formula is (length x seam allowance) + width. This formula calculates the product of the length and seam allowance and then adds the width. This formula is incorrect because the seam allowance should be considered for both dimensions.

In option C, the formula is (length + seam allowance) x (width + seam allowance). This formula adds the seam allowance to both the length and width separately, and then multiplies the adjusted dimensions. This formula is also incorrect because the seam allowance should not be multiplied.

In option D, the formula is (seam allowance x 2) + (length x width). This formula multiplies the seam allowance by 2, adds it to the product of length and width, and gives the total fabric needed. This formula correctly accounts for the seam allowance and calculates the area of the curtain.

Therefore, the correct formula for calculating the amount of fabric needed to make a curtain is option D: (seam allowance x 2) + (length x width).

None of those choices mentions hems and top treatment (rod pocket, etc.) Therefore, none of these answers is correct.