Răspuns:
a) teorema lui pitagora:
[tex] {c1}^{2} + {c2}^{2} = {i}^{2} [/tex]
c1=cateta 1(AB)
c2=cateta 2(AC)
i=ipotenuza(BC)
[tex] {ab}^{2} + {ac}^{2} = {bc}^{2} [/tex]
[tex] {5}^{2} + {12}^{2} = {bc}^{2} [/tex]
[tex]25 + 144 = {bc}^{2} [/tex]
[tex]169 = {bc}^{2} [/tex]
[tex]bc = \sqrt{169} [/tex]
[tex]bc = 13[/tex]
b) A=
[tex] \frac{c1 \times c2}{2} [/tex]
A=
[tex] \frac{ab \times ac}{2} [/tex]
A=
[tex] \frac{12 \times 5}{2} [/tex]
A=
[tex]30 {cm}^{2} [/tex]