Answer:
Pair 1: 10 cm and 2 cm. and the sum is 12 cm.
Pair 2: 20 cm and 4 cm. and the sum is 24 cm.
Step-by-step explanation:
Area of a rectangle is given by A = LW, where L is the length and W is the width of the rectangle.
Pair 1:
For the first rectangle W = 4 cm and A = 40 sq, cm
Then cm.
For the second rectangle W = 4 cm and A = 8 sq, cm
Then cm.
Therefore, the sum of two unknown lengths = 10 + 2 = 12 cm. (Answer)
Pair 2:
For the first rectangle W = 4 cm and A = 80 sq, cm
Then cm.
For the second rectangle W = 4 cm and A = 16 sq, cm
Then cm.
Therefore, the sum of two unknown lengths = 20 + 4 = 24 cm. (Answer)