• calculation of the perimeter of ∗ rectilinear figure ∗ rectangle ∗ square

What will we learn today?

MeasurementPerimeter

What is Perimeter?

The perimeter is the total distance around the outside of a 2D

shape.

Let’s recall some concepts.

Length is the longest dimension of an object.Breadth is the extent or measure of how broad or wide something is.

5cm

3cm

Length

Breadth

Perimeter of Simple Shapes

There are special formulas for certain shapes:For example:

What is the perimeter of this rectangle?Perimeter = Length + Length + Breadth + Breadth

5cm

3cm3cm

5cm

Summary

You can only find perimeter when the lengths and breadths have the same units.For example, the length is 5 cm and the breadth is 4 cm.The perimeter will be 18 cm.

Summary

You can only find perimeter when the length and breadth have the same units.For example, the length is 5 m and the breadth is 4 m.The area will be 18m.

A and B have the same area. Find the unknown length, x.

AB

64cm²x cm

A and B have the same area. Find the unknown length, x.

___ x ___ = 64cm²

AB

64cm²x cm

A and B have the same area. Find the unknown length, x.

8 x 8 = 64Therefore, x = 8cm

AB

64cm²x cm

2 similar rectangles overlapped each other.Find the perimeter of the figure.

4 cm

6 cm

8 cm

4 cm

2 similar rectangles overlapped each other.Find the perimeter of the figure.

4 cm

6 cm

8 cm

4 cm

The length and breadth have the same value.

2 similar rectangles overlapped each other.Find the perimeter of the figure.

4 cm

6 cm

8 cm

4 cm

6 + 8 + 4 + 6 + 8 + 4 = ______ cm

6 cm8 cm

2 similar rectangles overlapped each other.Find the perimeter of the figure.

4 cm

6 cm

8 cm

4 cm

6 + 8 + 4 + 6 + 8 + 4 = 36 cm

6 cm8 cm

Are you ready to try out the questions?

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