Area, SMB-015

A letterbox, which has been constructed by joining a half cylinder and rectangular prism, needs to be painted on each external surface.

Find the surface area of the letterbox, giving your answer correct to the nearest square centimetre. (3 marks)

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`9061\ text(cm)^2`

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`text{Surface Area (half cylinder)}`	`= \frac{1}{2} (2pi r^2 + 2pi rh)`
	`= \frac{1}{2} (2pi xx 17.5^2 + 2pi xx 17.5 xx 40)`
	`= 3161.227…\ text{cm}^2`

`text{SA (total)}\ = 3161 + 5900 = 9061\ text{cm}^2`