How to calculate quantity of bricks for a semi circular arch

Hello i am Engineer gohar in today article i will discussHow to calculate Quantity Bricks for semi circular arch. In thill discuss how two calculquantity of materials in arch. 1. Semi Circular Arch:Given:Span 7' Thickness = 1 ft Breadth = 1ftTo calculate the quantity of materials in semi circular arch we need to calculate the volume of arch.Volume of arch = Cross-section of arch x Arch lengthWe know Cross-section area = Thickness of arch x Breadth of archArch length = Circumference of half circle (The arch is semi circular)We know circumference of circle = 2πRCircumference of half circle = 2πR/2 = πR We don’t what is R. So we need to find out the ‘R’.for lenght of arch .and find the quantity of semi circular arch