The adjoining figure shows the cross-section of a railway tunnel. The radius of the tunnelis 3.5 m (i..e, OA = 3.5 m) and AOB = 90o. Calculate : (i) the height of the tunnel, (ii) the perimeter of its cross section, including base. (iii) the area of the cross-section. (iv) the internal surface area of the tunnel, excluding base, if its length is 50 m. (v) Find the cost of paining inner portion of the tunnel at the rate of 8 per sp. Meter. But payment was made on the basis of total inner surface area of the tunnel.(a) The height of the tunnel is (i) 5.37 m nearly (ii) 5.47 m nearly (iii) 5.97 m nearly (iv) 5.87 m nearly (b) The perimeter of its cross-section, including base is(i) 20.45 m nearly (ii) 21.45 m nearly (iii) 19.45 m nearly (iv) 21.95 m nearly(c) Area of the cross-section of the tunnel is(i) 28.48 m2(ii) 27.88 m2(iii) 28.88 m2(iv) 28.38 m2(d) The internal surface area of the tunnel, excluding base, if its length is 50 m.(i) 875 m2(ii) 845 m2(iii) 865 m2(iv) 855 m2(e) The cost of painting inner portion of the tunnel at the rate of 8 per seq. metre(i) 7500 (ii) 7000 (iii) 7200 (iv) 7400​