如何在三角形中畫1個圓

Step 1: Draw the angle bisectors of any 2 of the 3 angles of the triangle.
Step 2: The intersecting point of the 2 angle bisectors will be the centre of the circle inside the triangle ( called in -centre).
Note: To draw angle bisector, use the vertex of the triangle as centre to draw 2 arcs that cuts the 2 adjacent sides at point A and B, then use A and and B as centre to draw 2 arcs, joining the intersecting point of these 2 arcs with the vertex of the triangle will be the angle bisector.

首先,張每條邊畫一條對角線,
之後,用圓規的針插在三條線疊起的一點,and張圓規的筆放在其中一條對角線,
最後,畫個圓圈,完成!