Im agree with you, the angles of any triangle sum 180 degrees, thats math. The real problem is when we want to draw that triangles, our tools and senses has limits. Math is something theoric with theric limits and drawing is something real, with real limits, In theory we can do a lot of things, in the reality we has lot of limits. Think this, you have something with weight of 1 kg in the second floor of a building if you take that thing ando go to the fifth floor the weight will be diferent than 1, because the gravity is not the same, thats another example of the big diference between the teorical world and the real world.