Question

The altitudes of an equilateral triangle are equal.
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Answer 1

Answer:

Three kinds of cevians coincide, and are equal, for (and only for) equilateral triangles: The three altitudes have equal lengths. The three medians have equal lengths. The three angle bisectors have equal lengths.

Internal angle (degrees): 60°

Symmetry group: D3

Edges and vertices: 3

Answer 2

Answer:

If all the three altitudes of a triangle are equal, then the triangle is equilateral.