Me where do you find a half life plz 26 points if you me this hard question is on my science thing test

Match each law or principle to its description. 1. law of original horizontality sediment continues to spread in a flat plane until it hits an edge or runs out of material. 2. law of superposition the youngest strata are at the top and the oldest are at the bottom. 3. law of original lateral continuity sediment gets pulled down by gravity in a horizontal and flat layer. 4. law of cross-cutting or intrusive relationships if there is a fracture or intrusive feature seen in rock strata, it is younger than the rock strata.