how to create this...?

1.)  Use the link artwork as a template;

2.)  Create another Layer;

3.)  Use the top Layer as your drawing layer;

4.)  Draw the middle triangle first; duplicate it for the upper two triangles > rotate each to position into place > modify each to match existing;

5.)  Use Reflection tool ( Horizontal copy ) to create the bottom two triangles > move into position;

6.)  Create a gradient and apply to match existing.