Question : ABCD is a quadrilateral in which BD and AC are diagonals. Then, which of the following is true:

Question : If ABC is an equilateral triangle and D is a point in BC such that AD is perpendicular to BC, then:

Question : If $\frac{a^{2} - bc}{a^{2}+bc}+\frac{b^{2}-ca}{b^{2}+ca}+\frac{c^{2}-ab}{c^{2}+ab}=1$, then the value of $\frac{a^{2}}{a^{2}+bc}+\frac{b^{2}}{b^{2}+ac}+\frac{c^{2}}{c^{2}+ab}$ is:

Question : ABC is a right angle triangle and $\angle ABC = 90^{\circ}$. BD is perpendicular on the side AC. What is the value of $(BD)^2$?

Question : A point D is taken from the side BC of a right-angled triangle ABC, where AB is hypotenuse. Then: