Across
- 3. In __________ geometry triangle angle sums here are less than 180 degrees.
- 5. Mathematicians began questioning _____’s postulates.
- 6. Euclidean, spherical, and hyperbolic each have unique rules, especially about ____ Lines
- 8. Euclidean, spherical, and hyperbolic each have unique rules,about Triangle ____ as well.
Down
- 1. In _______ geometry parallel lines don’t exist, and triangle angle sums are greater than 180 degrees.
- 2. ____________geometries emerged in the 1800s.
- 4. Instead of assuming a flat space, they explored ________ surfaces.
- 7. In __________ geometry the sum of the angles is exactly 180 degrees.
