Library/Geometry/Plane geometry/Area/Lines and curves dividing figures into equal parts

Lines and curves dividing figures into equal parts

Overview
Important

A line or curve divides a figure into equal parts if it splits the figure into regions of equal area. For regular shapes, symmetry often helps find such lines. For irregular shapes, more advanced methods or calculations may be needed.

Important properties

  • For many shapes, lines of symmetry divide the figure into equal-area parts.

  • A straight line is not always the only way; sometimes a curve is needed (e.g., dividing a circle into two equal areas not through the center).

  • For polygons, drawing lines through certain points (like midpoints) can create equal-area regions.

  • For more than two parts, multiple lines or curves may be needed, and their placement depends on the shape's properties.