This document provides an overview of key concepts in statics including:
1) The parallelogram law states that the resultant of two forces is equal to the diagonal of a parallelogram constructed from the forces.
2) The triangle law states that three forces will be in equilibrium if their magnitudes are proportional to the sides of a triangle drawn in order.
3) Lami's theorem states that if three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two forces.
4. If two forces acting at a point be represented in
magnitude and direction, by the sides of a
parallelogram drawn from the point, their resultant
is represented both in magnitude and direction by
the diagonal of the parallelogram drawn that point
6. If three forces acting at a point can be represented
in magnitude and direction by the sides of a
triangle taken in order, they will be in equilibrium
8. If three forces acting at a point are such that their
magnitudes are proportional to the sides of a triangle
and their directions are perpendicular to the
corresponding sides, all inwards or all outwards, then
also the forces will be in equilibrium
10. If three forces acting at a point are in equilibrium,
then any triangle drawn so as to have its sides
parallel to the directions of the forces shall
represent them in magnitude also
12. If any number of forces acting at a point can
be represented in magnitude and direction by
the sides of a polygon taken in order, the
forces will be in equilibrium