The way to find the area depends on the shape:
- For a rectangle or square, multiply the length by the width:
Area=length×width\text{Area}=\text{length}\times \text{width}Area=length×width
- For a triangle, use:
Area=12×base×height\text{Area}=\frac{1}{2}\times \text{base}\times \text{height}Area=21×base×height
- For a circle, use:
Area=π×r2\text{Area}=\pi \times r^2Area=π×r2
where rrr is the radius. For compound shapes, split the shape into rectangles or simpler shapes, find their areas with the above formulas, and then add or subtract as needed. Area is measured in square units such as square centimeters (cm²) or square meters (m²) depending on the unit of length used.
