Respuesta :

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 [tex]L = \frac{A}{W} = \frac{40}{4} = 10[/tex] cm.

For the second rectangle W = 4 cm and A = 8 sq, cm

Then [tex]L = \frac{A}{W} = \frac{8}{4} = 2[/tex] 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 [tex]L = \frac{A}{W} = \frac{80}{4} = 20[/tex] cm.

For the second rectangle W = 4 cm and A = 16 sq, cm

Then [tex]L = \frac{A}{W} = \frac{16}{4} = 4[/tex] cm.

Therefore, the sum of two unknown lengths = 20 + 4 = 24 cm. (Answer)