Răspuns:
Explicație pas cu pas:
[tex]A_l = P_b \times h = 15 \times 10 = 150cm {}^{2} \\ [/tex]
[tex]P_b = 15 \Leftrightarrow 3l = 15 \Rightarrow l = 5cm[/tex]
[tex] A_b = \frac{l {}^{2} \sqrt{3} }{4} = \frac{5 {}^{2} \sqrt{3} }{4} = \frac{25 \sqrt{3} }{4} cm {}^{2} \\ [/tex]
[tex]A_t = A_l+2A_b = 150 + 2 \times \frac{25 \sqrt{3} }{4} = 150 + \frac{50 \sqrt{3} }{4} =\boxed{150 + \frac{25 \sqrt{3} }{2} cm {}^{2} }\\ [/tex]
