1 Let and be the altitudes of an acute triangle with on and on . Let be the point of intersection of and . Take any line through with on and on . Suppose and are located on and respectively. such that is perpendicular to and is perpendicular to . Prove that is parallel to .
1 Hayaan at ang altitudes ng isang matinding tatsulok may on at on . Hayaan ang punto ng intersection ng at . Lumabas sa anumang linya ng sa pamamagitan ng may on at on . Ipagpalagay at ay matatagpuan sa at ayon sa pagkakabanggit. tulad na ay tirik na at ay tirik na . Patunayan na ang ay Kahambing sa .