On n-sections and reciprocal quadrilaterals - Eisso J. Atzema We introduce the notion of an n-section and reformulate a number of standard Euclidean results regarding angles in terms of 2-sections (with proof). Using 6-sections, we define the notion of reciprocal (complete) quadrangles and derive some properties of such quadrangles. ✪ ✪ ✪ ✪ ✪ Link tải tài liệu: LINK TẢI TÀI LIỆU Theo LTTK Education