Question: Why was the area upset with the perimeter?

Answer: Because the area thought the perimeter always went around the problem.

**Perimeter **is the total distance taken up around the **outside of a shape.**

Can you think of examples of where perimeter might be used?

A good example is if you are fencing a field, or building a wall around something. You will need to know the perimeter.

To find the perimeter simply **add up all the lengths **of each shape.

**Example 1:**

When you have a missing length, such as in this example, break it down as shown above.

**Perimeter = 10 + 2 + 6 + 6 + 4 + 8 = 36 cm**

**Example 2:**

Calculate the missing length. If the slant height isn't given, you have to assume it is 4 cm.

**Perimeter = 4 + 10 + 10 = 24 cm**

**Example 3:**

The length of the semicircle can be calculated by finding the circumference and dividing by 2.

**Circumference = π x diameter**

The circumference of the circle is π x 12 = **37.70 cm **(Take the value of pi as 3.142)

To get the circumference of the semicircle: **37.70 ÷ 2 = 18.85 cm**

The missing length of the rectangle is** 11 cm**

**12 + 11 + 11 + 18.85 = 52.85 cm**

Let's move on to some questions now.