Question

ABC-isoscel
AC=AB=10cm
h=8 cm 
AE-inaltime
BC-?

Answer 1

ΔAEC este dreptunfhic in E.
Aplic teorema lui Pitagora in ΔAEC: $EC^{2}+ AE^{2}= AC^{2}=> EC^{2}= AC^{2}- AE^{2} => EC= \sqrt{ AC^{2}- AE^{2} }$=$\sqrt{100-64} = \sqrt{36}=6 (cm)$
BC=2EC=2*6=12 (cm).