.The inner diameter of a circular well is 3.5 m. It is 10 m deep. Find(1) its inner curved surface area,(2) the cost of plastering this curved surface at the rate of 40 per m2.​

Answer:(1 ) Inner curved surface area of the well is  109.9 sq. meters.(2) The cost of plastering the total curved surface area is  4396.Step-by-step explanation:The inner diameter = 3.5 m Depth of the well =  10 mNow, Diameter = 2 x Radius⇒R = D/ 2  = 3.5/2 = 1.75or, the inner radius of the well = 1.75 mCURVED SURFACE AREA of cylinder = 2πr h⇒The inner curved surface area =  2πr h  = 2 ( 3.14) (1.75)(10)                                                                       = 109 sq. metersHence, the inner curved surface area of the well is  109.9 sq. meters.Now, the cost of plastering the curved area is 40 per sq metersSo, the cost of total plastering total area = 109.9 x(Cost per meter sq.)                                                                     =  109.9 x (40)                                                                    =   4396Hence, the cost of plastering the total curved surface area is  4396.