A protractor is used to draw and measure angles. An angle is the amount of turn between two lines. Angles are measured in degrees with the symbol °. Angles can be labelled with 3 letters (eg DEF) to ...

Scales are number lines which can be straight or circular. The number line is split into intervals with divisions marked. You will see scales on measuring jugs, car speedometers, oven dials and many ...

Field-measured spectra are critical for remote sensing physical modelling, retrieval of structural, biophysical, and biochemical parameters, and other practical applications. We present a library of ...