Question

4 why dont the present shapes of the continents fit perfectly into a supercontinent?

Explanation:

Over time, after the supercontinent (like Pangaea) broke apart, the continents' edges have undergone changes. Erosion from wind, water, and ice has worn down coastlines. Also, sediment deposition (from rivers carrying sediments to oceans) has altered coastal shapes. Additionally, plate tectonics cause continental edges to subduct, collide, or rift, further modifying their outlines. These geological processes (erosion, deposition, tectonic activity) have reshaped the continents, so their current shapes don't align perfectly with a supercontinent's former structure.

Answer:

The present shapes of the continents don’t fit perfectly into a supercontinent because geological processes (erosion, sediment deposition, plate tectonics - subduction, collision, rifting) have reshaped continental edges since the supercontinent (e.g., Pangaea) broke apart.