2) given (because they already marked that on the picture)
3) N is vertically opposite to the angle above => N equals the angles above
JK is parallel to ML
JN = NL
4) KJN and MLN have alternate angles => equal
5) JN = NL
angle JNK = angle LNM
angle KJN = angle MLN
With what? I don't see a question
Answer:
a) Just add 1 square on the right and 1 square on top for figure 4. Add 1 more in each place for figure 5.
b) Each stage adds a square above and a square to the right. The pattern never decreases. This trend is shown by figures 1, 2, and 3.
c) Figure 0 would be a single square. Simply follow the pattern in reverse. As the figure number decreases, squares are removed from the right and the top rather than added.