This document defines key geometry terms like perimeter and area and provides formulas to calculate them for different shapes. It explains that perimeter is the distance around a shape and is calculated by adding all side lengths. Area is the measure of surface space within a shape and is reported in square units. Formulas are given for calculating the perimeter of rectangles using 2 * length + 2 * width and the perimeter of triangles using the sum of the three side lengths. The area of a shape is calculated by counting the number of squares (or units) that fit within the shape. Examples are provided to demonstrate calculating perimeter and area for different 2D shapes.

1. Geometry: Perimeter and Area

2. Can You Name the Shape?

3. Geometry: Perimeter and Area New Vocabulary: Perimeter: The distance around a geometric figure. Formula : An equation that shows a relationship among certain quantities. Area: The measure of the surface enclosed by a figure.

4. Width Definition: How wide a figure is from side to side.

5. Length Definition: The measure of the distance across an figure.

6. Perimeter To calculate the perimeter of any shape, just add up “each” line segment of the “fence”.

7. Perimeter 3 in 2 in 2 in 3 in

8. Perimeter 3 in 2 in 2 in 3 in P= 2 + 3 + 2 + 3 = 10 in You can find the perimeter of a rectangle by adding all of the sides together.

9. Find the Perimeter Using a Formula

10. PERIMETER OF A RECTANGLE P=2l+2w

11. 2 in. 3 in. Perimeter of a Rectangle P=2l+2w P=2(3 in.) + 2 (2in.) P=6 in. + 4 in. P=10 in.

12. PERIMETER OF A TRIANGLE P=s +s +s 1 2 3

13. Perimeter of a Triangle P=s + s + s 2 3 P=8cm+10cm+6cm P= 24 cm 8cm 6cm 10cm

14. Remember Squares ALL sides are equal…so if they give you one side, you know ALL the sides Length=the Largest side If they “leave” numbers out, they are equal to their opposite side. If they give you the bottom of a square/rectangle type shape then the top is the same

15. Finding area of an irregular figure Box the object in then count the length and the width of the “box”. Example: Length = 4 Width = 5

16. Find The Perimeter What is the perimeter of this figure?

17. Area Area is the amount of surface space that a flat object has. Area is reported in the amount of square units.

18. AREA Square units means that “that” many squares fit inside that shape (if measured in feet…it’s feet…if meters…it’s meters. In this example the area is 4 square units…note 4 squares fit) 1 2 units (ft, in, m) 2 3 4

19. Count the number of blue squares to determine the area of that surface. The area is equal to 9 squares.

20. Area = 15 square feet What is the area of this surface if each square is equal to one foot? Count the number of squares. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

21. Two neighbors build swimming pools. This is what the pools look like. Which family has the pool with the bigger swimming area?

22. The area of Family A’s pool is 8 square units. The area of Family B’s pool is 7 square units. Therefore, Family A has the pool with the bigger swimming area.

23. Area of Squares/Rectangles Length x Width=Area 2 Length(2) x Width(2) = 4 square units

24. Parallelogram Area Area=Base x Height (Area=length x width) BASE (length) Height (width) 8 5 Base 8 x Height 5 = Area 40 The diagonal line is NOT the height!!!