planimeter
/pləˈnɪmɪtər/
noun
- A mechanical or electronic instrument used to measure the area of a flat shape by tracing its outline.
- The old planimeter sat on the shelf, a relic from the days before computer software.
- In the drafting class, students learned how to use a planimeter to measure blueprints.
- The engineer used a planimeter to calculate the area of the irregular plot of land on the map.