Hi MM,
Point 1:
90 degrees for the angle is not what I proposed. I proposed an angle of ABC= i90 degrees(complex angle). That's a different kettle of fish.
Point 2:
In your statement with ABC=90. OK, Then BAC+BCA= 90 has an infinite number of solutions. What does your solution of 89*2=178 refer to?
Interesting you should mention Escher in one breath with hyperbolic geometry. The solution to sin(ix+y)is related to hyberbolic functions, but I do not know how to plot it!. Thanks anyway.
Conrad