Folosim Formula lui Heron
[tex] p = \frac{a + b + c}{2} [/tex]
[tex]p = \frac{20 + 21 + 13}{2} [/tex]
[tex]p = 27[/tex]
Atriunghi=
[tex] \sqrt{p(p - a)(p - b)(p -v )} [/tex]
[tex] \sqrt{27(27 - 20)(27 - 21)(27 - 13)} \\ [/tex]
[tex] \sqrt{27 \times 7 \times 6 \times 14} [/tex]
[tex] \sqrt{15876} [/tex]
=126 cm^2
