Home » Geometry » Regular 2D Shape Area Formulas

2d shapes are which drawn on plane. Have the property of area. Basic 2d objects include triangle, circle, rectangle, square, parallelogram, rhombus, irregular quadrilateral, n-polygon and etc.

**2d shape Area formulas:**

Triangle

It is a 2d shape that has 3 sides.

A = 1/2 x base * height

A = ( s x ( s – a ) x ( s – b ) x ( s – c ) )^{1/2}

where a, b, c are sides of triangle, s = ( a + b + c ) / 2

Circle

It has only on curved edge and every point one edge is equidistant from central point.

A = π x radius²

Circle Calculator – Calculate circle area and perimeter, sector area and arc length.

Square

This 2d shape has four equal length straight edges and all four corners are right angles.

A = side²

Rectangle

Parallel edges are equal in length. All four corners are right angles.

A = length x width

Parallelogram

Four side 2d shape having opposite sides as equal in length and parallel.

A = height x base

Rhombus

Four side 2d shape having four equal length edges.

A = 1/2 x diagonal1 x diagonal2

Trapezoid

It is a 2d shape having four straight edges. Only one pair of opposite edges are parallel.

A = 1/2 x height x (base1 + base2)