Perimeter The distance around the outside of a shape.

Perimeter The distance around the outside of a rectangle.

Perimeter To find the perimeter you need to measure the length of each side of the rectangle. then add them together.

Perimeter Measure each side of the triangle then add them together.

Circumference The distance around the outside of a circle. Distance across middle. Diameter Distance from middle to circumference. Radius

Perimeter The distance around the outside of a rectangle. length width Perimeter = (2 x L) + (2 x W)

Perimeter Do you have to measure every side to find the perimeter of these shapes?

Perimeter Word Problems

1.A regular pentagon has one side 25cm long. How long is the perimeter of this shape?

2. A regular hexagon has a perimeter of 300cm. How long is the length of one side?

2. A Hexagon has a perimeter of 300cm. How long is the length of one side?

3. A square field has a perimeter of 1200m. How long is the length of each side of the field? One side of the field is hedged. What length of fencing is needed to fence in the other three sides?

What is the perimeter of a square of side 20cm?

If the perimeter of square is 200cm. What is the length of one of the sides?

What is the perimeter of an equilateral triangle of side 8.9cm?

A regular heptagon has a side length of 26cm. What is it’s perimeter?

A rectangle has a perimeter of 68cm. It’s short side is 10cm. What is the length of the long side?

Finding Circumference

What Is Circumference Circumference is the distance all the way around a circle. The equation to find circumference is 2  r or  multiplied by the diameter of the circle.

Some Terms Defined  is said as pie, like the kind you eat – about 3.14 r is the radius of a circle – or half the distance across a circle d is the diameter of a circle – or the distance all the way across a circle – or two radii added together

How To Find Circumference If you have the radius: – Multiply the radius by 2 to get the diameter. – Multiply this answer by 3.14 (  ). If you have the diameter: – Multiply the diameter by 3.14 (  ).

Let’s Try A Problem Find the diameter or the radius. We are going to find the radius. What is the radius of this circle?

Problem Continued The radius is 5. Next, multiply the radius by 2 to get the diameter. Last, multiply the diameter by  or 3.14.

Problem Solved The circumference of the circle is 31.4.

Here’s Another Problem Find the circumference of this circle.

Solution The diameter is 6. Multiply the diameter by  (3.14). The Circumference is

We can work out the area of a rectangle without the grid. length width Area = length x width

Now work out the area of these rectangles. They are not drawn to scale. 36cm 2 35cm 2 20cm 2 25cm 2 4cm 9cm 7cm 5cm 4cm 2cm 12.5cm

A shape that is made from other shapes is known as a composite shape. To find the area of this shape we have to split it up into two rectangles. 10cm 8cm 2cm 4cm Area = 4 x 10 40cm 2 Area = 4 x 8 32cm 2 Total area = = 72 cm 2

Find the area and perimeter of each of these shapes? 9cm 5cm 2cm 4cm 5cm 4cm 2cm 11cm 7cm 4cm 3cm 7cm 6cm 11cm 2cm 4cm 5cm 4cm

9cm 5cm 2cm 4cm 5cm 4cm 2cm Area = 5 x 9 45cm 2 Area = 4 x 5 20cm 2 Total area = = 65 cm 2 Perimeter = 36 cm

6cm 11cm 2cm 4cm 5cm Area = 2 x 5 10cm 2 Area = 6 x 6 36cm 2 Total area = = 46 cm 2 Perimeter = 34 cm

11cm 7cm 4cm 3cm 7cm Total area = = 65 cm 2 Perimeter = 42 cm Area = 4 x 7 Area = 4 x 4 4cm Area = 3 x 7 21cm 2 28cm 2 16cm 2 There is another way of doing this question.

11cm 7cm 4cm 3cm 7cm Total area = 77 – 12 = 65 cm 2 Perimeter = 42 cm Area = 7 x 11 Area = 3 x 4 4cm 77cm 2 12cm 2