Triangles - Class X
Formulae, Relations, Theorems etc.
Basic Proportionality Theorem
If a line is drawn parallel to one side of triangle intersecting the other two sides in distinct points, the other two sides are divided in the same ratio.
Converse of Basic Proportionality Theorem
If a line divides any two sides of a triangle in same ratio then the line is parallel to the third side.
In a right triangle square of hypotenuse is equal to sum of squares of other two sides.
Converse of Pythagoras Theorem
In a triangle if square of one side is equal to sum of squares of other two sides then the triangle is a right triangle, right angled at angle opposite to the first side.
The ratio of the areas of two similar triangles is equal to the square of the ratio of their corresponding sides.