Answer: 12.3 cm
Explanation:
We are given the perimeter and all but one of the missing side lengths. The perimeter is equal to all of the side lengths added together. Using this information, we can create an equation to solve for the missing length, ?.
? = 65.9 cm - (9.2 cm + 4.7 cm + 4.7 cm + 2.2 cm + 9.2 cm + 2.2 cm + 12 cm + 4.7 cm + 4.7 cm)
? = 65.9 cm - 53.6 cm
? = 12.3 cm