CurriculumGrade 6Mathematics

Polygons on the Coordinate Plane

Aligned to 6.G.A.3 — Common Core State Standards for Mathematics.

What this lesson teaches

When a polygon's corners are given as coordinates, you can plot them and find a side's length by subtracting coordinates — horizontal sides use the x-values, vertical sides use the y-values.

Worked example

A rectangle has corners (1, 2), (6, 2), (6, 5), (1, 5). The bottom side length is 6 − 1 = 5, the left side is 5 − 2 = 3, so its perimeter is 2 × (5 + 3) = 16.

Practice questions

  1. Plot (2, 1), (2, 6) and find the length of that vertical segment.
  2. A square has corners (0, 0), (4, 0), (4, 4), (0, 4). Find its perimeter.
  3. Find the length of the side from (−3, 2) to (5, 2).

Watch the lesson

Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.

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En español

Polígonos en el Plano Cartesiano

Cuando los vértices de un polígono se dan como coordenadas, puedes ubicarlos y hallar la longitud de un lado restando coordenadas: los lados horizontales usan los valores de x, los verticales usan los de y.

Ejemplo: Un rectángulo tiene vértices (1, 2), (6, 2), (6, 5), (1, 5). El lado inferior mide 6 − 1 = 5, el lado izquierdo mide 5 − 2 = 3, así que su perímetro es 2 × (5 + 3) = 16.

More Geometry lessons

Area, Surface Area, and Volume6.G.A.1Volume with Fractional Edges6.G.A.2Nets and Surface Area6.G.A.4

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