Kehäpituus

Kehäpituus is a Finnish term that translates to "circumference" in English. It refers to the perimeter or the distance around a closed two-dimensional shape. This concept is fundamental in geometry and is applied to a wide variety of figures, including circles, squares, rectangles, and more complex polygons.

For a circle, the circumference is calculated using the formula C = 2πr, where 'C' represents the circumference, 'π' (pi) is a mathematical constant approximately equal to 3.14159, and 'r' is the radius of the circle. Alternatively, it can be calculated as C = πd, where 'd' is the diameter of the circle (twice the radius).

In the case of polygons, the kehäpituus is simply the sum of the lengths of all its sides. For a square with side length 's', the circumference is 4s. For a rectangle with length 'l' and width 'w', the circumference is 2l + 2w. Understanding and calculating kehäpituus is essential for determining the boundary length of shapes, which has practical applications in various fields such as construction, engineering, and design.