[tex]1. a^{2} + b^{2} = c^{2} \\\\ 7^{2} +3^{2}=x^{2} \\49+9=x^{2} \\58=x^{2} \\x=\sqrt{58} =7,6\\\\2. y^{2} +3^{2} = 3\sqrt{5}^{2} \\ y^{2} + 9 = 45\\y^{2}= 45-9\\ y^{2} = 36\\y=\sqrt{36} = 6\\\\3. h=\frac{a\sqrt{3} }{2} \\h=\frac{10\sqrt{3} }{2} = 5\sqrt{3}[/tex]
