Enter dimensions to calculate area. Supports circle, triangle, rectangle, square, parallelogram, trapezoid, ellipse, and regular polygon shapes.
Circle area formula: A = pi r^2, where r is radius. Example: a circle with radius 5m has area pi x 25 approx 78.54 m^2.
Triangle area: A = 1/2 x base x height. With three known sides, use Heron's formula.
Trapezoid area = 1/2 x (base_a + base_b) x height. Half the sum of parallel sides times height.
Regular polygon area = 1/2 x side^2 x n x cot(pi/n). This calculator uses side length and number of sides.
Ellipse area = pi x a x b, where a is the semi-major axis and b is the semi-minor axis length.