Given:⇒(i)r= radius=23.5​=1.75 , h= depth of the well=10m ⇒Curved surface area =2πrh=(2×722​×1.75×10)m2=110m2⇒(ii) Cost of plastering = Rs 40 per m2The cost of plastering the curved surface = Rs (110×40)= Rs 4400.