1. Area, Circumference & Perimeter
Polygon & Circles

2. Objective:
By the end of the class period, I will be able to solve using a formula for a given variable (A..REI)

3. Steps for Solving for Area/Perimeter/Circumference
Write the formula that applies
Substitute the number for the variable
Perform the operation (multiply everything together)

4. Perimeter of Square
P = 4(s)

5. Area of a Square
A = s2

6. Perimeter of Rectangle
P = 2(l) + 2(w)
Width
Length

7. Area of a Rectangle
A = (l)(w)
Width
Length

8. Perimeter of Parallelogram
P = add all sides outside the parallelogram

9. Area of a Parallelogram
A = (b)(h)
Height
Base

10. Area of a Triangle
A = ½(b)(h)
Height
Base Base

11. Area of a Trapezoid
A = ½ h(b1 + b2 ) b2
Height b1

12. Circumference of Circle
C = π d C = 2 π r π = 3.14

13. Area of a Circle
A = πr2
r = ½ d

14. Steps for finding the area of irregular polygons
What polygons (circle) do you see?
2. For step 2
If all of the shape is shaded (same color), you add
If part of the shape is shaded, you subtract

15. Steps for finding the area of irregular polygons
Which formula do you use?
Substitute the value
Solve by order of operation