(Solved): Mensuration 10 (a) The diagram shows a brass washer. The washer is made by removing a circular disc ...

Mensuration 10 (a) The diagram shows a brass washer. The washer is made by removing a circular disc of diameter \\( 1.6 \\mathrm{~cm} \\) from a circular disc of diameter \\( 2.4 \\mathrm{~cm} \\). (i) Find the area of the top surface of the washer in square centimetres. \\[ \\begin{aligned} & \\frac{2.4}{2}=1.2 \\\\ & \\left(1.2^{2} \\cdot \\pi\\right)-\\left(0.8^{2} \\cdot \\pi\\right) \\\\ = & 1.44 \\pi-0.64 \\pi \\\\ = & 0.8 \\pi \\\\ = & 2.51 \\quad \\text { Answer(a)(i) } \\ldots \\ldots \\ldots \\ldots \\ldots \\ldots \\ldots \\mathrm{cm}^{2} \\end{aligned} \\] (ii) The washer is \\( 2 \\mathrm{~mm} \\) thick. Calculate the volume of the washer in cubic centimetres.