This document provides instruction on calculating the areas of circles using the formula A = πr^2. It begins with examples of calculating areas given the radius. Later examples involve calculating the radius or diameter given the area. The document includes examples with step-by-step workings, as well as questions for students to practice. It concludes by having students fill out a KWL chart about their understanding of finding circle areas before and after the lesson.

1. AIM: Area of Circles
Do Now
Weekly Quiz #13
1

2. Weekly Quiz #13
Use the formulas we learned in class and
show all work.
1.) What is the sum of the measures
of the angles of a 7 sided polygon?
2.) Find the area of the following
figures. 3m
a.) b.)
5 in 6m
11 in
5m
2

3. Homework: Pages 426-427 #17-24 all, 33-41 all
3

4. 4

5. Anticipatory Set:
Fill the What I Know and What I Want to Learn
sections of the following KWL Chart based on your
knowledge of finding the area of a circle.
What I Know What I Want to Learn What I Learned
5

6. Area of a Circle Formula
1.) A = πr2
6

7. 1
Find the area of the following circle. Use the Pi Button and
round your final answers to the nearest hundredth.
7y
d
7

8. 2
Find the area of the following circle. Use the Pi Button and
round your final answers to the nearest hundredth.
cm
13
8

9. 3
A 153 m2
B 306 m2
C 23409 m2
D 46818 m2
Find the area and leave the answer in Pi notation.
Radius = 153 m
9

10. 4
A 2053 m2
B 4214809 m2
C 4106 m2
D 1053702.25 m2
Find the area and leave the answer in Pi notation.
Diameter = 2053 m
10

11. Determine a method to find the radius or diameter given the
area. Explain your method.
Given Radius Given Area
Square Radius
Multiply by Pi
You Found Area
11

12. 5
If the area of a circle is 56 centimeters2, find the
length of the radius and the diameter. Use the Pi
Button and round your final answers to the nearest
tenth.
Radius = _____
12

13. 6
The area of the Superdome in New Orleans is
362,984 feet2. Find the length of the radius and the
diameter of the Superdome. Use the Pi Button and
round your final answers to the nearest tenth.
Diameter = ______
13

14. 7
The area of a circle is 81π feet2. Find the radius and
diameter.
Radius = _____
14

15. BEFORE YOU LEAVE
Go back to the KWL Chart in the
Anticipatory Set and fill in the What
I Learned section.
15

16. Mr. Tjersland's Math 7
Homework: Pages 440-441 #6-8 all, 13, 14, 21-24 all, 26, 30-38 all
16