Conf. T lui Pitagora, din tr BAC - dr, BC^2= BA^2 +AC^2
AC^2= BC^2 - BA^2
AC^2= 400-256
AC^2= 144
AC=12cm
Conf. T catetei, AC^2=CD*CB
CD=AC^2 / CB
CD=144/20CD
CD=7,2cm
Conf. T catetei, AB^2= BD*BC
BD=AB^2/BC
BD=256/20
BD=12,8 cm
Conf. T inaltimii, AD^2= BD*CD
AD^2= 12,8*7,2
AD^2=92,16
AD=9,6 cm
Aabc = AB*AC/2
Aabc = 16*12/2
Aabc = 96cm^2
