Borrow a "chalk globe" from your instructor. Working with your group, make a triangle on the chalk globe by picking three points not too far apart and connecting the points with geodesics. You can make the geodesics by drawing a piece of string tight between a pair of points. Use a protractor to measure the angles of the triangle. Find the sum of the angles. Repeat the measurements using three points located fairly far apart on the chalk globe. Have the group discuss how the sum of the angles in your triangles compares with the sum of the angles in a plane triangle.