Isibali-manani sokubala esingenanto ngokwenza i-arch
R1 - Irediyasi yangaphakathi yeArch.
R2 - Irediyasi engaphandle yeArch.
S - Inani lamaqhekeza arch.
U - Icandelo lecandelo lesangqa.
Iimpawu.
Ukubalwa ubungakanani kunye nenani iinxalenye ekwenziweni arch ngomthi.