Answer: All of these items have sharp, jagged edges which were desgined to cut something.
Explanation: A lawnmower has large spinning blades that are sharp so that it can cut up the grass. Next, A razor has sharp edges to cut evenly down skin covered in hair (face, legs, etc). Lastly, ice skates have sharp edges to cut into the ice so that they can move freely and hold up the skater without them falling over. The skates also have a sharp spike groove to help stop quickly if needed.
