Question

find the value of BC

Answer 1

BD ⊥ AC

Therefore, ΔBDC is Right - Angled Triangle ...

Given That, BD = 4 & DC = 5

By Using Pythagoras Theorem, $\sqrt{Base^{2}+ Altitude^{2}} = Hypotenuse$

i.e. $\sqrt{BD^{2} + DC^{2}} = BC$

$\\ \sqrt{4^{2}+5^{2}} = BC\\ \\ BC = \sqrt{41}$