What is the minimum number of straight lines that is needed to construct the figure?
11
14
15
21
13
The horizontal lines are AE and JF i.e. 2 in number.
The vertical lines are AJ, CH and EF i.e. 3 in number.
The slanting lines are AG, BF, JD, IE, AB, DE, JI and FG i.e. 8 in number.
Total number of straight lines needed to construct the figure =2+3+8=13