Answer:
1. Broad mountain, flat top ⇒ Mesa
A Mesa is elevated like a mountain is and even though the edges are steep, it takes a broad shape. The top takes a flat shape which leads it to look like a table from afar.
2. Steep sides, flat top ⇒ Butte
Buttes are much like Mesas but are smaller in size which is why their sides are more steep than Mesas. While Mesas are wider than they are tall, Buttes are taller than they are wide on top.
3. Large, elevated plain ⇒ Plateau
A plateau is a general name for areas that are elevated but still relatively flat.
4. Vast area of flat land ⇒ Plains
Plains are a vast area of flat land with no or little elevation.