Pintaala

Pinta-ala is the size or measure of a two‑dimensional figure in a plane. In Finnish mathematics, pinta-ala refers to the region the figure covers and is expressed in square units, such as square meters (m^2) or square centimeters (cm^2). The pinta-ala is additive for non‑overlapping parts: the total area of a composite shape equals the sum of the areas of its components.

Common formulas for basic shapes include: a rectangle has area A = l × w, a square A = s^2, a parallelogram A = b × h, and a triangle A = (b × h) / 2. A trapezoid has A = ((a + b) × h) / 2, and a circle has A = π r^2. For regular polygons with n sides, A = (n s^2) / (4 tan(π/n)) or A = (1/2) p a, where p is the perimeter and a the apothem. For irregular shapes, the area can be found by decomposing the figure into simpler parts, or by integration in calculus, or by counting units in a grid model.

Applications of pinta-ala include land surveying, architecture, interior design, cartography, and the planning of sports fields. The concept is fundamental in geometry and appears in many practical tasks, from calculating floor space to estimating running tracks and plots of land.

In Finnish usage, pinta-ala denotes the area of a planar figure; surface area of three‑dimensional objects is treated as a related but distinct concept in geometry discussions.