Illustration of circle with inscribed angle 30 and central angle 60.

Groups of change with totals from 1 to 100 cents using the least amount of coins.

Regular hexagon with equilateral triangles divided in the interior.

30-60-90 Right Triangle

30-60-90 right triangle.

An isosceles triangle with angles 60, 60, 60

Steam pipe illustration of 30-60-90 triangle.