Unit 5, Lesson 5# The Area of Polygons Through Composition and Decomposition

EngageNY 45 min(s)

Students show the area formula for the region bounded by a polygon by decomposing the region into triangles and other polygons. Students find the area for the region bounded by a trapezoid by decomposing the region into two triangles. Students decompose rectangles to determine the area of other quadrilaterals. Decomposing irregularly shaped polygons into rectangles involves making a choice of where to separate the figure.