Viviani's theorem states that the sum of altitudes to all sides from a point inside one of these is equal to the length of its altitude. Morley's theorem states that one of th
Viviani's theorem states that the sum of altitudes to all sides from a point inside one of these is equal to the length of its altitude. Morley's theorem states that one of these is formed by extending the trisectors of a triangle. Napoleon's theorem states that a fourth one of these can be produced by joining the centroids of ones erected on the sides of any triangle, and they are the repeating units of a Koch snowflake and Sierpinski's triangle. For 10 points, identify these geometric figures which have three congruent sides.
Viviani's theorem states that the sum of altitudes to all sides from a point inside one of these is equal to the length of its altitude.
{equilateral} triangles [prompt on {equiangular} triangles; prompt on triangles]