[tex]Zadanie\\\\P=\frac{1}{2}\cdot a\cdot b\cdot sin\alpha\\\\ a)\\a=6\ cm\\b=10\ cm\\ sin\ 30^o=\frac{1}{2}\\\\P=\frac{1}{2}\cdot 6\cdot 10\cdot\frac{1}{2}=\frac{60}{4}=15\ cm^{2}\\\\b)\\a=5\ dm\\b=8\ dm\\sin\ 45^o=\frac{\sqrt{2}}{2}\\\\P=\frac{1}{2}\cdot 5\cdot 8\cdot \frac{\sqrt{2}}{2}=\frac{40\cdot \sqrt{2} }{4}=\sqrt{2}\ dm^{2}\\\\c)\\ a=\sqrt{3}\ m\\b=12\ m\\sin\ 60^o=\frac{\sqrt{3}}{2}\\\\P=\frac{1}{2}\cdot \sqrt{3} \cdot 12\cdot \frac{\sqrt{3}}{2}=\frac{12\cdot3}{4}=\frac{36}{4}=9\ m^{2}[/tex]
