A.50mm,100mm,200mm B.50mm,100mm,150mm C.10mm,50mm,100mm D.10mm,20mm,50mm
A.50mm,100mm B.10mm,50mm C.10mm,100mm D.10mm,20mm
A.T形截面 B.矩形截面 C.單筋截面 D.雙筋截面