Answer:
(b) Length = 30 feet, width = 20 feet
Step-by-step explanation:
The scale factor is applied to the drawing dimensions to find the actual dimensions.
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length = (6 cm) × (5 ft)/(1 cm) = 30 ft
width = (4 cm) × (5 ft)/(1 cm) = 20 ft
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Additional comment
You can also write the scale factor as part of a proportion:
5 ft : 1 cm :: x ft : 6 cm
Multiplying by 6 cm gives
(5 ft)(6 cm)/(1 cm) = x ft = 30 ft . . . . as above