There are a few ways to make a triangle in Illustrator. The easiest way is to use the command “line” and draw a line from one corner of the triangle to the other corner. The second way is to use the “line tool” and draw a line from one edge of the triangle to the other edge. The third way is to use the “polygonal tool” and create a polygonal shape by drawing a line around each vertex of the triangle. Finally, you can use the “ellipse tool” and create an ellipse by drawing a line through both ends of the triangle.