Finding Area
and Perimeter
Pre-algebra
Grade 7
Tangrams
Learning Objectives
Calculate areas by counting squares
Calculate area using formulas
Use the correct language for shapes, attributes and
formulas
The Tangram is made from cutting a square into 7 pieces
1
3
4
2
5
7
6
Write down the mathematical name for each of the 7 pieces.
Can you place the pieces in order of size, with the largest first?
Draw a tangram on square cm paper starting with a 16 by 16 square
Calculate the area and perimeter of the tangram
Method 1: counting squares
Method 2: Formulas: Perimeter – the sum of the sides
Rectangle – A= bh
Calculate the area and perimeter of each of the 7 pieces of the tangram
Method 1: counting squares
Method 2: Formulas: Perimeter and area
Calculate the area and perimeter of each of the 7 pieces
Rearrange the 7 pieces of the tangram to make a rectangle
Click on the
rectangle to see a
solution
Write down the area and the perimeter of the rectangle.
Area - A = bh
Rearrange the 7 pieces of the tangram to make the following
shapes
Trapezoid
Parallelogram
Right triangle
Back
Write down the area and the perimeter of the parallelogram.
Area - A = bh
Back
Write down the area and the perimeter of the trapezoid.
A= ½ h(b1 + b2)
Back
Write down the area and perimeter of the triangle
A= ½ h(b1 + b2),
Now that you have gathered your data, fill in the Area
and Perimeter worksheet.
Perimeter
Area
Directions: Use the data you have recorded in your journal to fill in the chart and answer the questions below.
List the following polygons from greatest to least by area, square, rectangle, parallelogram, trapezoid, triangle.
Draw a diagram of the polygon and label
it.
Indicate what lines you used to
determine the area.
Have extra time? Want to explore?
Try these!! Add them to your worksheet for extra credit
An animal
from the story
Pentagon
Hexagon
Make a design
of your own
Right Angled
Triangle
Find the area and perimeter of each shape.
Back
Back
This Powerpoint adapted from Tangrams Area and
Perimeter contributed to TES Connect by davecavill.
Retrieved from http://www.sharemylesson.com/teachingresource/Tangrams-Area-and-Perimeter-3012408/
© D Cavill
2005