A shop sign ABCDEFG is modelled as a uniform lamina, as shown above. ABCD is a rectangle with AB = 120 cm and BC = 60 cm. The shape EFG

is an isosceles triangle with EF = 40 cm and height 40 cm. The mid-point of AB and the mid-point of EF coincide. a) Explain why the centre of mass of the sign is 60 cm from side AD b)Find the distance of the centre of mass of the sign from the side AB. The sign is freely suspended from D and hangs at rest. c) Find the size of the angle between DC and the horizontal. Give your answer to the nearest degree.