a = 6√3
H = 10
[tex]h = \frac{a \sqrt{3} }{2} [/tex]
[tex]h = \frac{6 \sqrt{3} \times \sqrt{3} }{2} = \frac{18}{2} = 9[/tex]
[tex]y = \frac{2}{3} h[/tex]
[tex]y = \frac{2}{3} \times 9 = 6[/tex]
6² + 10² = x²
36 + 100 = x²
x² = 136
x = 2√34
