Add a student-friendly definition in the Binder Page editor.
Composite Figures and Scale Drawings
Students decompose composite figures and apply scale factors to lengths, perimeters, and areas.
Find It. Learn It. Master It.
At a Glance
How can a complex region be reorganized into simpler measurable parts?
A composite figure combines familiar shapes. Draw helpful boundaries, find missing dimensions, calculate each component, and add or subtract without double-counting.
A scale factor k multiplies every length. Perimeter changes by k, but area changes by k squared. Use the scale statement consistently and include units.
4,327 = 4,000 + 300 + 20 + 7
Learning Targets
- Decompose into known shapes.
- Find missing dimensions first.
- Add or subtract areas.
- Lengths scale by k.
- Areas scale by k squared.
Interactive Vocabulary
Add a student-friendly definition in the Binder Page editor.
Add a student-friendly definition in the Binder Page editor.
Add a student-friendly definition in the Binder Page editor.
Worked Examples
L-shaped region
Enclose it in a 10×8 rectangle and subtract a 4×3 cutout.
A=80−12=68 square units.
Rectangle plus semicircle
Add rectangle area and half a circle’s area.
Common Questions
Does area use the same scale factor as length? No, it uses k squared.
Can I split a figure in different ways? Yes, if pieces cover it exactly once.
Should a removed region be added? No, subtract it.
Common Misconceptions
Double-counting overlapping regions
Mark each nonoverlapping part.
Subtracting an unlabeled length incorrectly
Use aligned total lengths to infer it.
Watch, pause, and explain
Use the chapter markers, key vocabulary, and reflection prompts to stay actively engaged while you watch.
Practice until you can explain it
Move from a quick warm-up to guided practice, independent work, and deeper challenges.
Warm-Up
Directions: Solve the problem. Show your thinking, then enter only your final answer.
A 12×9 rectangle has a 4×3 corner removed. Find area.
Guided Practice
Independent Practice
Directions: Solve independently. Show your work, check it, then enter only your final answer.
A 12×9 rectangle has a 4×3 corner removed. Find area.
Directions: Solve independently. Show your work, check it, then enter only your final answer.
Create and solve a second example with different values.
Challenge & Real-World Practice
Design a composite figure with total area 150 square units. Provide two valid solution methods and compare their efficiency.
Nice work!
You completed the Practice It learning path.
IXL
Area of Compound Figures
Open resourceScale Drawings: Area and Perimeter
Open resourceKhan Academy
Scale Drawings
Open resourceComposite Area
Open resourceDeltaMath
DeltaMath: Composite Area
Open resourceDeltaMath: Scale Drawings and Area
Open resourceSave today’s lesson and grow your MathBinder
Collect lesson resources, revisit recent pages, build review packets, and watch your binder grow over time.
Printable Resources
Printable Lesson Notes
Guided notes that follow this lesson and are ready to print and place in your binder.
- Vocabulary
- Worked examples
- Guided notes
Practice Pages
Guided and independent practice pages for mastering today’s lesson.
- Guided practice
- Independent practice
- Challenge question
Challenge Problems
Stretch your thinking with higher-level questions, puzzles, and enrichment activities.
- Extension problems
- Math puzzles
- Enrichment
Teacher & Parent Resources
Answer keys, teaching tips, intervention ideas, extensions, and discussion prompts.
- Answer key
- Teaching tips
- Discussion prompts
Recently Added
My MathBinder
Build a Review Packet
My Collected Lessons
Create a printable list of the lessons saved in this browser.
Favorite This Lesson
Save this page for quick access from your MathBinder dashboard.
Continue Learning
Move to another published lesson in this Binder Section.
Open Perimeter and Circumference →Your Binder Achievements
Learned. Watched. Practiced. Saved.
Now capture the most important idea in My Math Journal.
Spend five minutes reviewing one saved lesson together each week. Ask your child to explain one example aloud.
My Math Journal
Capture your thinking, questions, and reflections. Everything is saved automatically on this device.
How confident do you feel?
Complete the thought
What do you want to remember?
My Journal History
Revisit reflections saved from other MathBinder lessons on this device.
Your Math Journal is automatically saved on this device.
Clearing your browser data will erase your saved journal entries.
Can you do this on your own?
Complete each question without hints. Your result is saved privately on this device.
Before you begin, I can…
- I can identify the important information.
- I can use accurate notation, labels, and units.
- I can justify and verify my conclusion.
What should happen before calculating?
Which response gives the strongest evidence?
What is an effective accuracy check?
Why are units or labels important?
What should a student do after finding an error?
How confident do you feel?
Your Results
Review and try again
Great job on Composite Figures and Scale Drawings!
You reviewed the lesson, practiced the skill, and completed the mastery check.