1.The cross sectional area of the rectangular beam (Figure la.) and the T beam (Figure .) is 24 cm2 , respectively. It is noted that the area moment of inertia of the rectangular area (with respect to the centroid (幾何中心）and x-axis {i.e. /Ixc)) is 72 cm4 {i.e. 4(63)/12 = 72cm4). Please locate the centroid
(C) of the cross-sectional area of the T beam, and then find the area moment of inertia (Ixc) of T beam as shown in Figure . What will be your comments if compare with the answer of Figure  and . ? (Note: the dimensions in Figures la and b are not in scales) (35%)簡易中文提示(詳 情請閱讀原題目）：圖la及lb截面積相等，求圖16的幾何中心及其面積慣性矩 (Ixc)，並與圖la的面積慣性矩比較，且寫出你的看法。注意：圖中各標記尺寸並不 一定等比例。