1. MG 2.1: PERIMETER & AREA RECTANGLES, SQUARES, TRIANGLES, CIRCLES Defining and calculating

2. Goal/Objective: Students will be able to: Use formulas routinely for finding the perimeter and area of basic two- dimensional figures and the surface area and volume of basic three- dimensional figures, including rectangles, parallelograms, trapezoids, squares, triangles, circles, prisms, and cylinders.

3. When your family puts up a new fence around your home, how will they know how much fencing they need? PERIMETER

4. Perimeter The perimeter of a figure is the distance all the way around the figure.

5. Perimeter The perimeter is found by adding the lengths of the sides together.

6. Find the perimeter of the figures. A.B. P = 24 m P = 21 cm

7. Perimeter of a Square A square is a figure with 4 equal sides. The perimeter can be found by adding all 4 sides together OR multiplying the side length by 4. So, P = 4s

8. Find the perimeter of the squares using the formula P = 4s. A.B. D. C. P = 36 m P = 28 in. P = 44 mm P = 20 cm

9. Perimeter of a Rectangle A rectangle is a figure with 4 sides. Opposite sides are equal. The perimeter can be found by adding all 4 sides together OR P = 2 w + 2 l

10. Find the perimeter of the rectangles using the formula P = 2 w + 2 l. A. B. D. C. P = 30 cm P = 28 m P = 54 mm P = 28 in.

11. If your parents want to put new carpet in your room, how will they know how much carpet to buy? AREA

12. Area The area of a figure is the number of square units that cover the surface of the closed figure.

13. Area A square unit is a unit that has 4 equal sides. For metric units, we say “units squared”. Ex: centimeters squared or cm 2 For U.S. Customary, we say “square units” Ex: square inches or sq. in.

14. Area The area of a figure is found by finding how many square units it takes to cover its surface.

15. Area of a Square The area of a square is found by finding how many square units it takes to cover its surface. Area of a square is: A = s x s or A = s 2

16. Find the area of the squares using the formula A = s 2. A. B. A = 16 cm 2 A = 25 sq. in.

17. Area of a Rectangle The area of a rectangle is found by finding how many square units it takes to cover its surface. Area of a rectangle formula is: A = l x w

18. Find the area of the rectangles using the formula A = l x w. A. B. A = 24 cm 2 A = 77 sq. in.

19. Perimeter of a Triangle Perimeter of Triangle= Sum of all sides P= 5 in + 7in + 11 in P= 23 in 11in 7in 5 in

20. Area of a Triangle Area of Triangle= 1/2 x (Base) x (Height) or bh/2

21. Circumference of a Circle

22. Example:

23. Formulas to Memorize! Perimeter of a polygon: add up the lengths of the sides Circumference of a circle: C=2 × π × r OR C= π × d Area of Rectangle: A= bh Area of Square: A=bh Area of a triangle A = ½ × b × h Volume of a rectangular solid: V=lwh Area of a Circle= A=πr2