Question

aflati lungimea laturii unui triunghi echilateral cu inaltimea de 8cm

Answer 1

h = l √3 supra 2 , formula inaltimii in triunghiul echilateral
l √3 supra 2 = 8
l √3 = 8 · 2
l √3 = 16
l = 16 supra √3, se rationalizeaza cu √3
l = 16√3 supra 3 cm

Answer 2

ABC= triunghi echilateral⇒ m<A=m<B=m<C=60
BE=inaltime    BE=8 cm
m<EBC=m<BEC-m<C=90-60=30⇒EC=8:2=4 cm
m<ABE=m<B-m<EBC=60-30=30⇒AE=8:2=4 cm
AC=AE+EC
AC=4+4=8 cm ⇒ AB=AC=BC=- 8 cm