2. Quadrilateral nature: The inscribed number 8 can be regarded as a quadrilateral, with two adjacent sides being tangent to a circle and the other two sides being line segments with the diameters of two circles. The two opposite sides of this quadrilateral are equal in length.
3. Equal area: Because the inscribed figure of 8 is the inscribed shape of a circle and can be divided into two equal triangles, the areas of the two triangles are also equal. 4. Features of the circle: The radius of the inscribed circle in figure 8 is equal to half the length of two line segments and coincides with the center point of the quadrilateral.