A circle that is tangent to two sides of a triangle, as the Malfatti circles are, must be centered on one of the angle bisectors of the triangle (green in the figure). These bisectors partition the triangle into three smaller triangles, and Steiner's construction of the Malfatti circles begins by drawing a different triple of circles (shown dashed in the figure) inscribed within each of these three smaller triangles. In general these circles are disjoint, so each pair of two circles has four bitangents (lines touching both). Two of these bitangents pass "between" their circles: one is an angle bisector, and the second is shown as a red dashed line in the figure. Label the three sides of the given triangle as , , and , and label the three bitangents that are not angle bisectors as , , and , where is the bitangent to the two circles that do not touch side , is the bitangent to the two circles that do not touch side , and is the bitangent to the two circles that do not touch side . Then the three Malfatti circles are the inscribed circles to the three tangential quadrilaterals , , and . In case of symmetry two of the dashed circles may touch in a point on a bisector, making two bitangents coincide there, but still setting up the relevant quadrilaterals for Malfatti's circles.