[{"term": "Perimeter", "definition": "The total distance around the outside of a shape."}, {"term": "Area", "definition": "The amount of space inside a two-dimensional shape, measured in square units."}, {"term": "Volume", "definition": "The amount of space inside a three-dimensional shape, measured in cubic units."}, {"term": "Radius", "definition": "The distance from the center of a circle to its edge."}, {"term": "Diameter", "definition": "The distance across a circle through its center; equal to 2 × radius."}, {"term": "Vertex", "definition": "A point where two sides of a shape meet (corner)."}]