If the interior angles of a spherical triangle add up to 252 degrees, what fraction of the sphere's surface is inside the triangle? Answer: 1/10th The spherical excess is the sum of the interior angles in excess of 180 degrees. (E=252 -180= 72deg) The ratio of the spherical excess to 720 degrees is equal to the ratio of the area of the triangle to the area of the sphere. triangle area/sphere area = 72/720= 1/10. |

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