| A | B |
|---|
| altimeter | an instrument that measures the height at which an object, such as an aircraft, is located. |
| barometer | an instrument that measures the air pressure of the atmosphere and is widely used in the study and forecasting of weather. something that shows a change; an indicator: wealth is sometimes considered a barometer of success. |
| diameter | a straight line segment that passes through the center of a circle or sphere with both of its ends on the boundary. the length of such a line. |
| geometry | the branch of mathmatics dealing with measurements and relationships of points, lines, angles, surfaces, and shapes. |
| kilometer | a unit of length equal to 1000 meters, or about 0.6214 mile. |
| metric | referring to a system of weights and measures based on units of 10, 100, and 1000. |
| metronome | an instrument used to mark time in steady beats at various speeds. |
| micrometer | an instrument used for measuring very small distances. |
| odometer | an instrument that measures distance traveled by a vehicle. |
| perimeter | the sum of the lengths of the segments that form the sides of a geometrical figure such as a polygon or circle. the outer boundary of such a figure. the outer limits of an area. |
