Scholastic
Study Jams! Area of Irregular Figures
Painting an irregular figure can be tricky if we don't know the exact area. This interactive presentation reveals that irregular figures can be broken into smaller, simple figures that use the area formulas. Go through two examples,...
Curated OER
Measurement: Lesson 2
Fourth graders find the perimeter of a geometric shape by adding the lengths of the sides. They find the area of a square or rectangle by counting square units. Students use multiplication to find the area of a rectangle. They estimate...
Texas Instruments
Texas Instruments: Numb3 Rs: Irregular Polygon Centroids
Based off of the hit television show NUMB3RS, this lesson has students explore finding the centroid of an irregular polygon by finding the mean of the coordinates of the polygon's vertices. Further, students find the centroid given that...
CK-12 Foundation
Ck 12: Elem Math: Counting Different 2 D Shapes Within Simple Composite Figures
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to dientify various two dimensional shapes within a composite figure.