Calculate the quantity of arch work in a flat arch over a door of 1.50 m width which subtends an angle of 600 at the centre and forms an equilateral triangle.
Assume thickness of arch and breadth of wall to be 40 cm and 30 cm respectively.1
0.36 m3
2
0.18 m3
3
0.407 m3
4
0.207 m3