Please read this thread
https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/Skew-Symmetric-Matrices/m-p/720432
about how to ask homework-type questions.
Here is what I wanted you to read:
when you ask for help you need to show what you've tried so far. Explain what you know and what you are confused about. Post some PROC IML code that indicates how you are attempting to solve the problem.
proc iml;
A = hadamard(4)/2;
I=A**2;
print A,I;
quit;
If your question is answered, please mark an answer as "Accepted" and mark the question as "Resolved." Otherwise, please let us know what additional information you need.