The Federal Aviation Administration (FAA) shares the Environmental Protection Agency's (EPA) concerns about lead emissions from small aircraft. Owners and operators of more than 200,000 piston-engine aircraft operating in the United States rely on aviation gasoline (avgas) to power their aircraft.
Symmetry (noun). a due proportion of the several parts of a body to each other; adaptation of the form or dimensions of the several parts of a thing to each other; the union and conformity of the members of a work to the whole. Symmetry (noun).
Line Symmetry. Basically, a line of symmetry is a line that divides a figure into two mirror images. The figure is mapped onto itself by a reflection in this line. A set of points has line symmetry if and only if there is a line, l, such that the reflection through l of each point in the set is also a point in the set. (May also be referred to as reflectional symmetry.). Certain figures can be mapped onto themselves by a reflection in their lines of symmetry.