To draw any geometrical figure, the most important things are the elements of that figure. Every figure has got such elements. On most occasions, the sides and the angles of a certain figure are known as the elements of that figure. On some occasions, even the diagonals are also an integral part of elements.
Let us Consider a Triangle
Three angles and three sides are the six elements of a triangle. All These six elements help to draw any given triangle. But in reality only a specific set of three elements are enough to draw a particular type of triangle. The other
three elements are fulfilled automatically.The group of these three elements is known as the Tests of triangles. Following are the four possibilities –
 To construct a triangle when all the three sides are known
 To construct a triangle when two angles and their included side are known
 To construct a triangle when two sides and their included angle are known
 To draw a rightangled triangle when one side and the hypotenuse are known

These are four possibilities when one
About Quadrilaterals
Four angles, four sides and two diagonals make up for the ten elements of a quadrilateral. Out of these ten elements, a systematic group (posibilities) of five elements is required to draw the given quadrilateral. it is then observed that the remaining five elements are fulfilled automatically.
Here is the list of those conditions:
 To draw a quadrilateral when three arms and two diagonals are known
 To draw a quadrilateral when three arms and the two included angles are known
 To draw a quadrilateral when four sides and any one diagonal are known
 To draw a quadrilateral when two adjacent arms and three angles are known
Remember, as said above, the diagonals are an integral part of quadrilaterals.