Developed by Caroline W.
How do you find the area of an odd shape?
Students should know:
- Basic multiplication and addition
- The concepts and formulas of perimeter and area
- Length x Width= Area of a rectangle or square
- Base x Height x ½ = Area of a triangle
- All of the side lengths added together = perimeter
- The formula Length x Width = Area only applies to rectangles and squares
- How to take measurements using feet and inches
- How to draw a large shape to scale on paper
- Measuring tape
- 2-3 sheets of paper
- Markers or colored pencil
Ask an adult for assistance to measure hard to reach places. Do not stand in chairs or use ladders unsupervised.
Step 1: Gather all your materials and find a room in your house that you would like to redesign on your paper.
How can I find perimeter and area relate to my yard outside?
Step 2: Draw a rectangle, a square, a triangle and the shape below on your paper. Use your measuring tape to help you make your lines straight and even. They can be big or small but try to take up most of the paper with the 4 shapes.
Step 3: Cut out the shapes and attempt to find the perimeter and area the shapes using inches. Record your measurements on paper.
Which shapes were easy to find both area and perimeter, and why?
Step 4: Use the rectangle, square, and triangle to make one large shape. Lay them together with no gaps or overlaps.
Before we measure anything, what do you already know about your new shape?
Step 5: Add the areas of your three individual shapes that you already collected. This will give you the area of the new shape you created.
How can you use your knowledge of perimeter and area to accurately find the area of 4th, odd shape you originally cut-out?
Step 6: Look around your room at all the different shapes and sizes of the floor and walls. Draw the shapes you see on your paper.
What kind of jobs have to use perimeter and area every day?
Step 7: Measure the sides of each wall or the base of the floor. Find the shape on your paper that matches your walls/ floor and record the real measurements. Use either all inches (78 in.) or all feet (6.5 ft.). Using both (6ft. and 6 in.) might be confusing as you multiple and add later on.
How do you know when to use perimeter, area, or both?
Step 8: If you want to paint the walls, find the area of each wall so you know how much paint to get. If you want to tile or carpet the floor, find the area of the floor. If you want to know if get new trim or hang up stringed lights, find the perimeter.
Are any of your walls oddly shaped? If so, how can you break them up into familiar shapes?
How will knowing the perimeter and area of a room affect what you can put in it?
Step 9: Add any new furniture or decorations to your drawing. Color your drawing, and have fun designing!
How will it affect what you can hang on the walls?
Step 10: With parent/guardian permission, share the results of your activity on social media using #AUHomeWorks!
Last modified: November 10, 2020