Answer:
option 4
Step-by-step explanation:
let the side of the square be s , then
length of rectangle = s + 14 and width = s - 4
Since the areas are equal then
s² = (s + 14)(s - 4) ← distribute using FOIL
s² = s² + 10s - 56 ( subtract s² - 56 from both sides )
56 = 10s ( divide both sides by 10 )
5.6 = s
Then
area of square = s² = 5.6² = 31.36 cm²