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本通報1953年1-2月號發表的“東北敬部編譯「平面幾何」中的三個作圖題”一文中第一題“求作一圓,切於已知角的一邊上的已知點,而於另一邊上截取一弦等於已知綫段”,現有文成宜和王麗庭兩位同志提出另外的解法,但兩位同志的解法賞大致相類,為省篇幅,我們經過改寫合併發表於下。 設P是已知角XOY的OX邊上的一個已知點,l為已知綫段,假定所求圓已經作出,它切OX於P點,截OY得AB弦,有AB=l(這裹AB與OY同向)。今將P點依OY的方向平移至Q點,使PQ=l,於是PQBA為平行四邊形;再以直綫OY為軸將Q點反射得Q′點,則有
This Bulletin, published in the January-February 1953 issue of the “Three Drafting Questions in the Compilation of ”The Plane Geometry“ in the Tohoku Ministry of the Tombs,” is the first item in the article “Shall be a circle, cut to a known point on one side of a known angle.” On the other side, intercepting a string is equal to the known line segment. The existing Wen Chengyi and Wang Liting comrades proposed another solution, but the two comrades’ rewards are roughly the same, saving space, and we have rewritten and published Let P be a known point on the OX edge of the known angle XOY, where l is a known line segment, assuming that the desired circle has already been made, it cuts OX at P point, cuts OY to AB string, and has AB=l (This wraps AB and OY in the same direction.) Now shift P point to Q point in the direction of OY, so that PQ = l, so PQBA is a parallelogram; then Q is reflected by Q point with the line OY as the axis. Have