question 9 and 30

part C. Long Answer. Show full solutions to achieve full marks. p. Show that ut us impossible to form a 20 cm length of wire into a rectangle with area 30 cm'. [T/1=2] [0-2] 30. During the transportation of thorium-243 to the nuclear power plant, a spill occurred near Springfiled. The town was evacuated and the residents were allowed to return home when the thorium-243 decayed to one-eight of its original radioactivity. If the half-life of thorium-243 is 24 days, after how long were the residents allowed to return home?[A=2] [c=4]