Polygons having five or more sides that are of different lengths are considered irregular shapes. Calculating the perimeter and area of irregular shapes can be a bit more challenging than finding the perimeter and area of regular shapes like squares or rectangles.
Perimeter Of Irregular Shape :
Perimeter is the total length of the boundary of any shape or the sum of all the sides of any shape. It is always measured in linear units like m, cms, Km, etc.
Area Of Irregular Shape :
Areas of irregular shapes are difficult to determine so by following any of these 2 simple ways, the area of such irregular shapes can be estimated :
- Evaluating area using unit squares
- Divide the given irregular shape into unit squares using this technique. The overall area of the shape is equal to the sum of all the unit squares that fall within it.
- For a more precise estimation of the area, count the square as “1” if the shaded area encompasses more than half of it.
- In the following figure, calculate the area by counting the unit squares, which is 8. If we denote each unit square in centimeters, the area will be 8 cm2.
- Dividing the irregular shape into two or more regular shapes
- Divide the shape : Divide the irregular shape into smaller, regular shapes that you know how to calculate the area of. For example, you can divide the shape into rectangles, triangles, or squares.
- Calculate the area of each part : Calculate the area of each smaller shape that you have divided the irregular shape into. Use the appropriate formula for each shape. For example, the area of a rectangle is found by multiplying its length and width, and the area of a triangle is found by multiplying its base and height and dividing the result by 2.
- Add up the areas : Once you have calculated the area of each smaller shape, add them together to find the approximate total area of the irregular shape.
It’s important to note that this method will provide an estimate of the area, as the irregular shape may not perfectly fit into the regular shapes you have divided it into.
Teaching perimeter and area of irregular shapes with kid-friendly, clear, and easy-to-understand posters from Uncle Math School by Fun2Do Labs :
Ignite kids’ curiosity with engaging stories for role play and skits, making the learning of this concept an exciting and effective experience. Teaching perimeter and area of irregular shapes through stories from Uncle Math School by Fun2Do Labs :
Learning the perimeter and area of irregular shapes can be made enjoyable by incorporating interactive games and activities.
Draw And Determine!
This is one of the most exhilarating activities for kids to understand the concept of finding areas of irregular shapes. This activity can be carried out in the following steps :
- Take the children to the garden and instruct them to collect leaves of 3 different shapes.
- Distribute graph paper to the children.
- Instruct children to trace leaves on graph paper.
- Explain how to calculate the area of the irregular shapes of the leaves by counting the unit squares covered by each leaf.
- Instruct children to report answers in centimetre square units.
Help your kids practise perimeter and area of irregular shapes with interesting and engaging fun worksheets and solutions from Uncle Math by Fun2Do Labs.