Explanation:
Every regular polygon can be constructed with equally sized isosceles triangles.
A pentagon can be constructed with 5 triangles;an hexagon, with six triangles.
In the center of the hexagon all the triangles will meet, like pizza slices.
Then, each of those angles in the center of the hexagon will be 360/6= 60 degrees.
As the other two angles of each triangle have to be congruent, we can say each angle has (180-60)/2=60 degrees.
Then, we can say the hexagon can be built with 6 equilateral triangles.
If we had a circle that passes through all the vertex in the hexagon, each side of each triangle will be the same lenght than the circle radius.
To costruct the hexagon we can draw a circle with a compass and, without changing the angle of the compass, put the point of the compass in some point of the circle and draw a curve that crosses the circle.
Then place the point of the compass in the intersection of the curve and the circle, and draw another curve that crosses the circle.
Repeating this operation 6 times we will have 6 equidistant points around the circle.
To draw the hexagon, make 6 lines that pass through 2 consecutive points in the circle.