Area of Composite Figures

Inside the case file

Area of composite figures activities, compound shapes worksheets, and rectilinear area practice for 4th grade, 5th grade, and 6th grade math are all included in this Mini Mystery Detective pack. Students break each irregular figure into rectangles, add the parts to find the total area, then use their answers to eliminate suspects and unmask the villain. Perfect for geometry review, math centers, morning work, early finishers, sub plans, and test prep, and completely no prep - just print and go.

Every side length is labeled on the diagram, and measurements are given in US customary units - square feet and square inches.

What's Inside

• Finding the area of composite figures by decomposing them into non-overlapping rectangles
• Recognizing area as additive: add the parts to find the whole
• Working with L-shapes, T-shapes, U-shapes and C-shapes
• Reading side lengths off a labeled diagram and deciding which lengths to multiply
• Recording answers in square feet and square inches, with the unit on every answer line
• Real-world contexts: playground plans, garden beds, classroom carpet, mural panels and poster boards
• Red-ink answer keys for every case

Five detective cases to solve: The Playground Swap, The Garden Dig-Up, The Carpet Tile Caper, The Mural Mix-Up and The Poster Board Cut. Answer keys included for every case.

What is a Mini Mystery Detective?

A Mystery Detective is a print-and-solve detective activity - like a classroom escape room without the locks or the prep. Every answer matches one suspect's ID badge, so each figure a student works out crosses another name off the list. The badge left unmatched at the end belongs to the villain, which makes the page self-checking: if two suspects are still standing, something needs another look. Real skill practice, critical thinking, and a detective hook that keeps the whole class working.

When to Use This Resource

• Geometry review before state testing
• Math centers and small groups
• Morning work and bell ringers
• Early finishers and enrichment
• Substitute teacher plans
• Homework and spiral review
• End-of-unit measurement and geometry practice

Grade Levels

Designed for 4th grade, 5th grade and 6th grade measurement and geometry. Also beneficial for struggling 7th graders who need extra practice with area, or advanced 3rd graders ready to move beyond simple rectangles.

Why Teachers Love Mystery Detectives

• Zero prep - print and hand out
• Self-checking, so students catch their own mistakes before you do
• Every figure is drawn and fully labeled, with no measuring required
• Whole-number answers throughout, so the focus stays on decomposing the shape
• Detective storyline keeps reluctant mathematicians working to the last question
• Works for independent practice, partners, small groups or a whole-class challenge

Love this resource?

Follow Kiwiland Education to discover more Mystery Detectives, geometry and measurement activities, and detective-themed stories for elementary classrooms.