$\"\"$

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The vertices of triangle are $\"\"$ .

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Distance between three dimensional points is $\"\"$ .

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Find the lengths of the sides of the triangle by using distance formula.

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Find the length of $\"\"$ .

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Consider $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .

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Find the length of $\"\"$ .

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Consider $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .

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Find the length of $\"\"$ .

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Consider $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .

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The two sides of the triangle are equal, $\"\"$ .

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Therefore, the triangle is isosceles triangle.

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$\"\"$

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The triangle is isosceles triangle.