60 (number) geometry, it is the number of seconds in a minute, and the number of minutes in a degree. In normal space, the three interior angles of an equilateral triangle each measure 60 degrees, adding up to 180 degrees. Because it is divisible by the sum of its digits in base 10, it is a Harshad number. A number system with base 60 is called sexagesimal (the original meaning of "sexagesimal" is sixtieth). It is the smallest positive integer that is written with only the smallest and the largest digit of base 2 (binary), base 3 (ternary) and base 4 (quaternary).
Isosceles triangle near-cancellation between the semiperimeter and side length in those triangles. If the apex angle formula_7 and leg lengths formula_8 of an isosceles triangle are known, then the area of that triangle is: This is a special case of the general formula for the area of a triangle as half the product of two sides times the sine of the included angle. The perimeter formula_10 of an isosceles triangle with equal sides formula_2 and base formula_3 is just As in any triangle, the area formula_5 and perimeter formula_10 are related by the isoperimetric inequality This is a strict inequality for isosceles