Definition of equilateral in English:



  • Having all its sides of the same length.

    ‘an equilateral triangle’
    • ‘The Von Koch snowflake is a fractal which is constructed from an equilateral triangle as follows.’
    • ‘An equilateral triangle produces one of the observed crop-circle patterns; three isosceles triangles generate the other crop-circle geometries.’
    • ‘For example, it's possible to slice a square into four angular pieces that can be rearranged into an equilateral triangle.’
    • ‘The vibration exciter and geophone were placed near the burrow with burrow opening, exciter and geophone occupying the three corners of an equilateral triangle having sides one meter in length.’
    • ‘As long as the three triangles are equilateral, the ‘midpoint ‘triangle is also equilateral.’’
    • ‘Any given triangle, either imagined or on paper, must either be acute, right, or obtuse, and either scalene, isosceles, or equilateral, and so any given triangle cannot represent all triangles.’
    • ‘One way to draw a Reuleaux triangle is to start with an equilateral triangle, which has three sides of equal length.’
    • ‘Then divide it into three equal pieces, and replace the middle piece with the other two sides of the equilateral triangle that has this middle piece as its base.’
    • ‘For a given individual, the values of the three coefficients in the ancestry vector q are given by the distances to each of the three sides of the equilateral triangle.’
    • ‘Now, both the original Asymmetric Propeller and Napoleon's theorem start with three equilateral triangles and discover the fourth one by construction.’
    • ‘But the image of the centroid of the equilateral triangle (which is, of course, the point of intersection of its medians) will be different, as indicated in Figure 6.’
    • ‘An equilateral triangle of side length one is called a unit triangle.’
    • ‘The sides of this equilateral triangle will be five million kilometres long.’
    • ‘As an equilateral triangle rolls over one catenary, it ends up bumping into the next catenary’
    • ‘In 1772, J.L. Lagrange identified a periodic orbit in which three masses are at the corners of an equilateral triangle.’
    • ‘Naturally, the axes form equilateral triangles - 27 of them.’
    • ‘The theorem thus implies existence of the total of 18 equilateral triangles.’
    • ‘If each edge has the same length and each face is an equilateral triangle, the result is a regular tetrahedron - one of the Platonic solids.’


Late 16th century: from French équilateral or late Latin aequilateralis, from aequilaterus ‘equal-sided’ (based on Latin latus, later- ‘side’).