Final answer:
When a compass is not available, techniques such as using the sun, landmarks, and stars can be used to determine the four cardinal directions.
Step-by-step explanation:
When a compass is not available, there are several techniques that can be used to determine the four cardinal directions.
1. Using the sun: By observing the position of the sun, you can determine the east-west directions. In the northern hemisphere, the sun rises in the east and sets in the west. In the southern hemisphere, it rises in the east and sets in the west, but in the opposite direction.
2. Using landmarks: If you are familiar with the area, you can use landmarks, such as mountains, rivers, or buildings, to determine the directions. For example, if you know that a mountain range is to the west, then you can use it as a reference point.
3. Using the stars: At night, you can use the stars to determine the directions. The North Star, or Polaris, is located close to the North Pole, so if you can find it, you can determine the north direction.