Calculate a Circle's Circumference

Given an integer radius from 1 through 1000, calculate the circle's circumference using π = 3.14159. Round to two digits after the decimal point using…

Given an integer radius from 1 through 1000, calculate the circle's circumference using π = 3.14159. Round to two digits after the decimal point using round-half-up, then return decimal text with exactly two fractional digits.

- `radius` is an integer in the inclusive range 1..1000. - Use π = 3.14159. - Round half-up to exactly two fractional digits and return a string.

Example 1: input radius = 1; output "6.28". 2 × 3.14159 × 1 rounds to 6.28.

Example 2: input radius = 2; output "12.57". The thousandths digit is 6, so the hundredths value rounds from 56 to 57.

Example 3: input radius = 250; output "1570.80". The exact value is 1570.795; a halfway value rounds up.

Category: Math & Numbers. Topic: math. Difficulty: Easy. Patterns: math.