Answer:
2(4x(5x) + 4x(6) + 5x(6)) = 720
20x² + 54x = 360
10x² + 27x - 180 = 0
x = (-27 ± √(27² - 4(10)(-180)))/(2(10))
= (-27 ± √7,929)/20
= (-27 ± 3√881)/20
= (-27 + 3√881)/20
length = 4((-27 + 3√881)/20)
= (-27 + 3√881)/5 m
breadth = 5((-27 + 3√881)/20)
= (-27 + 3√881)/4 m
