A=c1*c2/2=216
c1*c2=432
AB/AC=3/4
AB=3AC/4
AB*AC=432
3AC/4* AC=432
3AC²=4*432
AC²=4*432/3
AC²=576
AC=24
AB=3*24/4=18
ΔABC,mas<A=90
BC²=AB²+AC²=18²+24²=576+324=900 ⇒BC=30
AD=AB*AC/BC= 24*18/30=432/30= 144/10
AB²=BD*BC
18²=BD*30
324=BD*30
BD=324/30=108/10
DC=30 -108/10 aducem la acelasi numitor
DC=300-108/10
DC=192/10=96/5