¶ Spherical Triangle Sequence
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Spherical Triangle Sequence:
"looking at my first picture that your eye does not want to see the bigger triangular area.
"I find this biased concept very important because as it plays such a big part in how competently or incompetently we conceive of and think about our environment.
"Those are what we call spherical triangles and you probably are not familiar with spherical triangles because you have been educated to start with planar triangles wherein the sum of the angles . . . is always 180 degrees.
“In a spherical triangle the angles never add up to 180°. To comprehend that fact let us go to the north pole and follow south along a meridian to impinge perpendicularly upon the equator, i.e., at 90°, and go along the equator a quarter of the way around the Earth. Then take a meridian back to the north pole. Taking the northbound meridian we leave the equator at 90° and, since we went a quarter of the way around the Earth, the two meridians followed-- first southbound and then northbound-- will form another 90° angle at the north pole. (Figure 1) Therefore we have”
