2. PERIMETER

3. Definition Add up all sides of the object 2 5 P = 2 + 2 + 5 + 5 P = 14

4. Example 3cm 6cm 5cm 3+6+5 P = 14 5cm 2cm 5cm 2+2+5+5 P = 14

5. Now…You!!

6. Area of rectangles Area is the space inside a 2D shape.

7. How do we calculate area? Measure the length. Measure the width. Multiply the length X width to calculate the area!

9. Area of Squares Side 3cm 3 cm. Side A square has all sides the same length. Therefore, we do not need a length and a width. We can simply call them sides. The area of a square can be calculated by multiplying side by side…or side squared.

10. Area of a square is given by: A = a 2 where a = length of side

12. But what if you want to calculate the area of an irregular shape? What if the shape has more than 4 sides? How can you do? Length X Width when there isn’t a length and there isn’t a width?

13. YOU HAVE TO MAKE RECTANGLES! Look at this shape. How could you calculate the area? 10cm 6cm 4cm

14. You have to create more than one rectangle. Like this! 10cm 6cm 4cm A = 6cm X 4cm = 24cm 2 B = 6cm X 4cm = 24cm 2 A + B = Area 24cm 2 + 24cm 2 = 48cm 2 A B

15. So to calculate the area of an irregular shape Split the shape into at least two rectangles. Calculate the area of each one. Add the two together. You’re done!

16. Great job!