A. 1 Article B.2, Article C.3 and Article D.4.

Answer d

This paper analyzes the calculation and judgment of spatial sense and line-line angle, and focuses on examining students' ability of classification, classification and transformation. The first category: there is a diagonal line AC 1 on the straight line passing through point A between three sides, and the second category: outside the figure, the included angle between the outer angle of each side and the other two sides is equal, and there are three lines, totaling four lines.