143) The maximum spacing of vertical stiffeners is[where d is the distance between flange angles]

144) The range of economical spacing of trusses varies from

145) The maximum permissible span of asbestos cement sheets is

146) Normally, the angle of roof truss with asbestos sheets should not be less than

147) To minimize the total cost of a roof truss, the ratio of the cost of truss to the cost of purlins shall be