Environment - Entry Fields
Entry Field Options
Up/Down spinners
Enables the arrows to the right of every length/angle field. These allow quick incrementing/decrementing by a specified amount.
Angle Zingers
Enables the angle icon to the right of every angle field. This button allows the display of the Angle Zinger for quick angle calculations.
Negators
Enables the 
button at the start of appropriate entry fields. This button allows you to quickly switch a number from positive to negative and vice versa.
History Lists
Enables a pulldown list for all length and angle fields, showing the previously used values.
Drop down height
Specify the number of items to appear in History Lists.