CHAPTER – 6
TRIANGLES
IMPORTANT THEOREMS
BASIC PROPORTIONALITY THEOREM OR THALES THEOREM
If a straight line is drawn parallel to one side of a triangle intersecting the other two sides, then it
divides the two sides in the same ratio.
, CONVERSE OF BASIC PROPORTIONALITY THEOREM
( CONVERSE OF THALES THEOREM)
If a straight line divides any two sides of a triangle in the same ratio, then the line must be parallel to
the third side.
TRIANGLES
IMPORTANT THEOREMS
BASIC PROPORTIONALITY THEOREM OR THALES THEOREM
If a straight line is drawn parallel to one side of a triangle intersecting the other two sides, then it
divides the two sides in the same ratio.
, CONVERSE OF BASIC PROPORTIONALITY THEOREM
( CONVERSE OF THALES THEOREM)
If a straight line divides any two sides of a triangle in the same ratio, then the line must be parallel to
the third side.
