+33616 Do you mean an equilateral triangle? If so, the altitude is a factor of (√3)/2 times the size of one side. If the perimeter is 66, one side is 22, so the altitude is:
$${\frac{{\mathtt{22}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{3}}}}}{{\mathtt{2}}}} = {\mathtt{19.052\: \!558\: \!883\: \!257\: \!650\: \!2}}$$
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+33616 Do you mean an equilateral triangle? If so, the altitude is a factor of (√3)/2 times the size of one side. If the perimeter is 66, one side is 22, so the altitude is:
$${\frac{{\mathtt{22}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{3}}}}}{{\mathtt{2}}}} = {\mathtt{19.052\: \!558\: \!883\: \!257\: \!650\: \!2}}$$
.
