Riddle: You are in your home, and your air conditioning is broken. The temperature in your house is 40 degrees. To warm yourself up, do you stand in an acute corner, or an obtuse corner?
Answer: An obtuse angle because it will be at least 91 degrees.
Riddle: Something that requires our mental skill to decode it, our imagination to understand it, and our knowledge to be tested to its max, it confuses us at every stage, it seems easy yet difficult, and only those who are used to, will get through. What is it?