Finding the Area of Irregular Shapes
What are Irregular Shapes?
Irregular shapes are shapes that have sides and/or angles of different lengths and sizes, i.e. the sides are not all of equal length, and/or the interior angles are not all the same size.
Area of the Green Shape
Area of the Blue Shape
Area of the Orange Shape
What did you notice about the three shapes? Is there are connection between their areas? *Use the tool below to help you answer this question*
Finding the area of Irregular Shapes
To find the area of irregular shapes, you will decompose the irregular shape into regular shapes, such as triangles or regular polygons, then find the area of each of the regular shapes and add them together.
Some of the common regular shapes used when decomposing irregular shapes are rectangles, squares, triangles, circles or semicircles, and trapezoids.
Example
This irregular shape was split into two shapes, a rectangle (shape A) and a square (shape B). Find the area of the rectangle and the area of the square, and then add the two areas together.
Irregular Shape 1
Irregular Shape 1
What is the Area of the Orange Irregular Shape above? (Units^2)
Irregular Shape 2
Irregular Shape 2
What is the Area of the Orange Irregular Shape above? (Units^2)
Irregular Shape 3
Irregular Shape 3
What is the Area of the Orange Irregular Shape above? (Units^2)
What steps did you take to solve the problems above? Make a numbered list.
What is the total area of the dog run? (don't forget units)
What is the size of the dog run not including the part filled with water?