By Kat Walcott, updated March 24, 2022
Use these straightforward formulas to determine the area of any two‑dimensional shape. Once you master the basics, you can tackle more complex polygons with confidence.
The area is found by multiplying one side by itself: A × A or A². For example, a square with side length 5 cm has an area of 5 × 5 = 25 cm².
Multiply the length by the width: L × W. A rectangle 6 cm long and 8 cm wide covers 6 × 8 = 48 cm².
Break the shape into simple rectangles or triangles, calculate each area, then add them. An L‑shaped figure composed of a 5 × 3 cm rectangle and a 9 × 2 cm rectangle has an area of 5 × 3 + 9 × 2 = 15 + 18 = 33 cm².
Use the base‑height formula: Base × Height ÷ 2. A triangle with a 10 cm base and 7 cm height occupies 10 × 7 ÷ 2 = 35 cm².
Apply π × radius². A circle with a radius of 3 cm has an area of π × 3² ≈ 3.142 × 9 ≈ 28.28 cm².
By applying these formulas, you can quickly compute the area of most 2‑D shapes in any field, from design to construction.
