Question 1171
 The trees should be as five star shape,but it is hard to draw there.

 You can try to draw a regular pentagon(say ABCDE) and then connecting the 5
 diagonals(5 rows) AC, AD, BE,BD, and CE to form the star. Plant the 10 trees 
 at the 5 vertices A,B,C,D,E and the 5 intersections points of diagonals.
 Andyou can see there are 4 trees on each of the diagonal row.

             A  
         B       E

           C    D