A model is built from 1 cm cubes. The plan is a 3 by 3 square. The heights at each plan position are as follows: the central position has height 3; every other position (the 8 surrounding cells) has height 2.
(a) Work out the total number of small cubes used.
(b) Work out the volume of the model in cubic centimetres.
(c) Work out the total external surface area of the model in cm2. Show your method clearly.
(a)Work out the total number of small cubes used.(3)
(b)Work out the volume of the model in cubic centimetres.(1)
(c)Work out the total external surface area of the model in cm2. Show your method.(6)
(Total for Question 10 is 10 marks)