Răspuns:
Explicație pas cu pas:
Problema 282
[tex] P_{romb} = 4l = > 4 l = 40 \: cm = > l = 10 \: cm \\ A_{romb} = {l}^{2} \cdot \: \sin( \angle{B}) = {(10 \: cm)}^{2} \cdot \: \sin(45 \degree) = 100 \: {cm}^{2} \cdot \frac{ \sqrt{2} }{2} = \frac{100 \sqrt{2} {cm}^{2} }{2} = \boxed{ \bold{50 \sqrt{2} {cm}^{2} }}[/tex]
Problema 283
[tex]A_{romb} = \frac{D \cdot \: d}{2} = \frac{35 \: cm \cdot8 \: cm}{2} = \frac{280 \: {cm}^{2} }{2} = \boxed{ \bold{140 \: {cm}^{2} }}[/tex]
