Menu Close

Let-ABC-be-a-triangle-and-h-a-the-altitude-through-A-Prove-that-b-c-2-a-2-4h-a-2-As-usual-a-b-c-denote-the-sides-BC-CA-AB-respectively-




Question Number 22079 by Tinkutara last updated on 10/Oct/17
Let ABC be a triangle and h_a  the  altitude through A. Prove that  (b + c)^2  ≥ a^2  + 4h_a ^2 .  (As usual a, b, c denote the sides BC,  CA, AB respectively.)
$$\mathrm{Let}\:{ABC}\:\mathrm{be}\:\mathrm{a}\:\mathrm{triangle}\:\mathrm{and}\:{h}_{{a}} \:\mathrm{the} \\ $$$$\mathrm{altitude}\:\mathrm{through}\:{A}.\:\mathrm{Prove}\:\mathrm{that} \\ $$$$\left({b}\:+\:{c}\right)^{\mathrm{2}} \:\geqslant\:{a}^{\mathrm{2}} \:+\:\mathrm{4}{h}_{{a}} ^{\mathrm{2}} . \\ $$$$\left(\mathrm{As}\:\mathrm{usual}\:{a},\:{b},\:{c}\:\mathrm{denote}\:\mathrm{the}\:\mathrm{sides}\:{BC},\right. \\ $$$$\left.{CA},\:{AB}\:\mathrm{respectively}.\right) \\ $$
Commented by ajfour last updated on 11/Oct/17
solved. See Q.22116
$${solved}.\:{See}\:{Q}.\mathrm{22116} \\ $$

Leave a Reply

Your email address will not be published. Required fields are marked *