Interactive
Shodor Education Foundation

Shodor Interactivate: Area (Elementary)

For Teachers 2nd - 5th Standards
In this lesson students will practice finding the area of rectangular shapes and irregular shapes with right angles and understand why the area formula works for rectangular shapes. CCSS.Math.Content.3.MD.C.5.b A plane figure which can...
Unit Plan
Shmoop University

Shmoop: Basic Geometry: Area of Irregular Shapes

For Students 9th - 10th Standards
The geometry resource investigates the area of irregular shapes. Detailed examples and practice exercises are included.
Activity
Government of Alberta

Learn Alberta: Math Interactives: Exploring Composite Figures

For Students 6th - 8th
Investigate how a variety of shapes can be used to form composite figures using this interactive Learn Alberta math resource. Students will also work on using relevant operations and formulas to figure out the total area of composite...
Unit Plan
Khan Academy

Khan Academy: Decompose Figures to Find Area 2

For Students 2nd - 4th Standards
Practice decomposing irregular shapes to find their area. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints. CCSS.Math.Content.3.MD.C.7.d Recognize area as additive.
Lesson Plan
PBS

Pbs Learning Media: Formulas: Targeted Math Instruction

For Teachers 9th - 10th Standards
At the end of this lesson plan about formulas, students will be able to identify and apply the correct formula for a given situation, solve for any unknown component of the formulas for perimeter, circumference, and area of regular and...
Activity
National Council of Teachers of Mathematics

Nctm: Figure This: Chocolate (Pdf)

For Students 3rd - 8th
Here's a delicious math challenge for chocolate lovers! Use your estimation and measurement skills to discover which irregular shaped, chocolate covered cookie has the largest surface area. A one-page activity from the NCTM Math...
Unit Plan
Khan Academy

Khan Academy: Area of Composite Shapes

For Students 5th - 7th Standards
Practice finding the areas of complex shapes that are composed of smaller shapes. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Mg How Many Leaves on a Tree? (Version 2)

For Teachers 9th - 10th Standards
In this task, students must estimate the number of leaves on a large tree, taking into account various complex factors such as the area shaded by the tree, the area of irregularly shaped leaves, the uneven distribution of leaves, the...