Stim ca e triunghi dreptunghic
AB=18cm
AC=24cm
BC=?
BD=?
DC=?
AD=?
Aplicam teorema lui Pitagora
BC²=AB²+AC²
BC²=324cm²+576cm²=900cm²
BC=√BC=√900cm²
BC=30cm
Aflam BD
Teorema catetei:
AB²=BD*BC=>BD=AB²:BC
BD=324cm²:30cm=10,8cm
BD=10,8cm
BC=BD+DC=>DC=BC-BD
DC=30cm-10,8cm=19,2cm
DC=19,2 cm
Aflam AD cu teorema inaltimii
AD²=BD*DC
AD²=10,8cm*19,2cm=207,36cm²
AD=√207,36cm²
AD=14,4 cm