The first par t evaluated a person's ability to identify 20 equilateral triangles as either red or green.
An equilateral triangle of side 30, would have a half side of length 15 and an altitude close to 26 in height.
These shapes include the ellipse (which was a check on our numerical scheme), an egg-shaped cross-section, a square, a rectangle, and an equilateral triangle.
The three quadrats in a given block were arranged at the points of an equilateral triangle with 5-m-long sides.
Among regular figures (equal length sides, equal angles), there are just three shapes that tessellate in this way: squares, equilateral triangles and hexagons.
Knowing something about equilateral triangles, it is easy to predict that the rule will apply to create an emergent hexagon.
First, inscribe within the sphere a regular icosahedron, which has 20 faces that are equilateral triangles.
The body is in the shape of an equilateral triangle flanked by two blue wings at the front.