In \(AD\bot BC\) prove that AB² + CD² = BD² + AC². 

BL and CM are medians of a triangle ABC right angled at A.
Prove that 4(BL² + CM²) = 5BC².

Prove that in a right triangle, the square of 8. the hypotenuse is equal to the sum of the squares of the others two sides.

In figure 0 is any point inside a rectangle ABCD. Prove that OB² + OD² = OA² + OC²

In \(\angle ACD={ 90 }^{ 0 }\) and \(CD\bot AB\) Prove that \(\cfrac { { BC }^{ 2 } }{ { AC }^{ 2 } } =\cfrac { BD }{ AD } \)