Answer:
B, C
Explanation:
perimeter of polygon = sum of lengths of sides of the polygon
A rectangle is a polygon that has 4 sides. Each 2 opposite sides are congruent. Perimeter = L + L + W + W = 2(L + W).
For a rectangle,
perimeter = 2(L + W)
perimeter = 19.2a - 24.4b
Choice A.
L = -9.3b - 10.2a
W = 18.9b - 4.1a
perimeter = 2(L + W)
perimeter = 2(-9.3b - 10.2a) + 2(18.9b - 4.1a)
perimeter = -18.6b - 20.4a + 37.8b - 8.2a
perimeter = 19.2b - 28.6a
perimeter = -28.6a + 19.2b
We need: perimeter = 19.2a - 24.4b
Choice A is not an answer.
Choice B.
L = 15.8a - 13.7b
W = 1.5b - 6.2a
perimeter = 2(L + W)
perimeter = 2(15.8a - 13.7b) + 2(1.5b - 6.2a)
perimeter = 31.6a - 27.4b + 3b - 12.4a
perimeter = 19.2a - 24.4b
We need: perimeter = 19.2a - 24.4b
Choice B is an answer.
Choice C.
L = 10.9b - 4.1a
W = 13.7a - 23.1b
perimeter = 2(L + W)
perimeter = 2(10.9b - 4.1a) + 2(13.7a - 23.1b)
perimeter = 21.8b - 8.2a + 27.4a - 46.2b
perimeter = 19.2a - 24.4b
We need: perimeter = 19.2a - 24.4b
Choice C is an answer.
Choice D.
L = 7.4a - 18.2b
W = 6b + 2.2a
perimeter = 2(L + W)
perimeter = 2(7.4a - 18.2b) + 2(6b + 2.2a)
perimeter = 14.8a - 36.4b + 12b + 4.4a
perimeter = 26.8a - 32b
We need: perimeter = 19.2a - 24.4b
Choice D is not an answer.