a) BD=20cm; DC=5cm
Teorema înălțimii: AD²=BD*DC
AD²=BD*DC=20cm*5cm=100cm²
AD=10cm
b)BD=8cm; AD=12cm
AD²=BD*DC=>DC=AD²/BD
DC=144cm²/8cm
DC=18cm
c)AD=6cm; DC=9cm
AD²=BD*DC=>BD=AD²/DC
BD=36cm²/9cm
BD=4cm
d)AB=6cm; AC=8cm; BC=10cm
AD*BC=AB*AC=> AD=AB*AC/BC
AD=6cm*8cm/10cm=4,8cm
e) AD=0,5cm; BC=20dm=200cm
AD*BC=AB*AC
AB*AC=0,5cm*200cm=100cm²=1dm²
f)BC=35cm; BD=DC/4
BD+DC=BC
DC/4+DC=35cm /*4
DC+4DC=140cm
5DC=140cm => DC=140cm/5
DC=28cm=> BD=28cm/4
BD=7cm
AD²=BD*DC=28cm*7cm=196cm²
AD=14cm
AC²=AD²+DC²=196cm²+784cm²=980cm²
AC=14√5 cm
AB=AD²+BD²=196cm²+49cm²=245cm²
AB=7√5 cm
