6.G.A.1: Area of polygons

Also written as 6.G.1

Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.

In plain words: Students find the area of triangles, special quadrilaterals, and other polygons by cutting them into rectangles and triangles or by building them up.

Quick picks

Common mistake
Forgetting the ½ for a triangle, or using a slanted side as the height: base 6 and height 5 give 15, not 30.
Builds on
3.MD.C.7Area and multiplication4.MD.A.3Rectangle area and perimeter
Leads to
6.G.A.4Nets and surface area7.G.B.6Area, volume, surface area
Example Problems
Approximate the area between the x-axis and from to using a trapezoidal sum with 3 equal subdivisions.
What is the approximate area?
Approximate the area between the x-axis and from to using a trapezoidal sum with 4 equal subdivisions.
What is the approximate area?
Approximate the area between the x-axis and from to using a midpoint Riemann sum with 3 equal subdivisions.
What is the approximate area?
Khan Academy Resources
Area of parallelogramsArea of trianglesArea of parallelogramsArea of trapezoidsArea of trianglesFind missing length when given area of a triangleArea challengeArea of right trianglesFind missing length when given area of a parallelogramDecompose area with trianglesArea of composite shapesFind base and height on a triangleArea of a triangleFinding area by rearranging partsArea of a parallelogramArea of composite shapesArea of trapezoidsArea of kitesArea of quadrilateral with 2 parallel sides
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