Answer:
1.time zones
2.The coriolis effect
3. triangles
Step-by-step explanation:
1. day and night happen at different times at different places; it's always day somewhere and night another.
2. the coriolis effect means freely moving things (like cannonballs or hurricane winds) are deflected to the right - but only if your north of the equator if you're south of the equator they're deflected left.
3. if you walk a certain distance and make three right angle you can successfully make a triangles with three 90 degree angles which is impossible on a flat surface.