Question

Fie ΔABC,m(A)=90⁰ şi AD perependicular pe BC,D∈BC
a)Daca BD=20 cm şi DC=5 cm , calculaţi AD.
b)Daca BD=8 cm şi AD=12 cm , calculati DC
c)Daca AD=6cm si DC=9cm,calculati BD
d)Daca AB =6cm si AC=8cm si BC=10cm,calculati AD
e)Daca AD=0.5cm si BC=20dm,calculati AB*AC
f)Daca BC=35cm si CD=4cmBD,calculati BD,DC,AD

Answer 1

a) ad² =bd·dc ⇒ ad² = 20·5 ⇒ ad= √100 ⇒ ad= 10 cm
b) AD²=BD·DC⇒12²=8· DC⇒DC = 12² :8 =144:8 ⇒DC = 18 cm
c) AD²=BD·DC⇒ 6²= BD ·9 ⇒ BD=6² : 9= 36:9 ⇒BD =4 cm