: Ncert solutions class 9 chapter 13-5 Let ABC be a conical tent Height of conical tent, h = 10 m Radius of conical tent, r = 24m Let the slant height of the tent be l. (i) In right triangle ABO, we have AB2 = AO2+BO2(using Pythagoras theorem) l2 = h2+r2 = (10)2+(24)2 = 676 l = 26 Therefore, the slant height of the tent is 26 m. (ii) CSA of tent = πrl = (22/7)×24×26 m2 Cost of 1 m2 canvas = Rs 70 Cost of (13728/7)m2 canvas is equal to Rs (13728/7)×70 = Rs 137280 Therefore, the cost of the canvas required to make such a tent is Rs 137280.