To find base diagonal $ d $ use Pythagorean Theorem:

$$ h^2 + \frac{ d^2 }{ 4 } = e^2 $$

After substituting $h = 66\, \text{cm}$ and $e = 65\, \text{cm}$ we have:

$$ \left( 66\, \text{cm} \right)^{2} + \frac{ d^2 }{ 4 } = \left( 65\, \text{cm} \right)^{2} $$ $$ \frac{ d^2 }{ 4 } = \left( 65\, \text{cm} \right)^{2} - \left( 66\, \text{cm} \right)^{2} $$ $$ \frac{ d^2 }{ 4 } = 4225\, \text{cm}^2 - 4356\, \text{cm}^2 $$ $$ d^2 = -131\, \text{cm}^2 \cdot 4 $$ $$ d^2 = -524\, \text{cm}^2 $$

This equation has no solution $ \Longrightarrow $ The problem has no solution.

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