Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or...
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Transcript of Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or...
![Page 1: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/1.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
Do Now:
1.Solve 5 + 2[(92 – 4) + (23 + 1)]
2.Solve and graph x + 11>25
3.Find the LCM of 48 and 90.
![Page 2: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/2.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
diameter d
radius r
circumference C
CIRCLE
Center - the point located in the middle of a circle
Diameter - the distance across the circle through the center.
Radius - the distance from the center to any point on the circle
Circumference: the distance around the circle
![Page 3: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/3.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
Radius r = 3 cm
Diameter d = 6 cm
Diameter is twice the length of the radius.
d = 2r
![Page 4: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/4.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
42 cm
8mm
5 in
Diameter = Radius = Radius =
Find the diameter or radius of each object.
1. 3.2.
10 in 21 cm 4 mm
Find the Diameter or Radius of a Circle
![Page 5: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/5.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
C = dπCircumference of a Circle
C = 2rπ
8mm
C = dπ
= 8π
5 in
C = 2rπ = 2(5)π
= 10π
42 cm
= 42π
C = dπ
Find the Circumference of a Circle
Find the circumference of each object. Round your answer to the nearest tenth.
1. 2. 3.
≈ 25.1mm
≈ 31.4in
≈ 131.9cm
![Page 6: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/6.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
d = 55 cm
1.
2.
r = 18 in
3. r = 2.5 ft
Find the Circumference of a Circle
C = dπ C = 2rπCircumference of a Circle
Find the circumference of each object. Round your answer to the nearest tenth. C = dπ
= 55π
≈ 172.8cmC = 2r π = 2(18)
π
≈ 113.1in
= 36π
C = 2r π = 2(2.5) π
≈ 15.7ft
= 5π
![Page 7: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/7.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
5 ft
Practice - Find the circumference of each circle. Round your answer to the nearest tenth.1. 2. 3.
19 in2 mm
1km
100 yd
6. 5. 4.
26 cm
Find the Circumference of a Circle
![Page 8: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/8.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
A = πr2
Area of a Circle
8mm 5 in
42 cm
Find the Area of a Circle
Find the area if each object. Round your answer to the nearest hundredth.
A = πr2
A = π42
A = 16π
1. 2. 3.
A = πr2
A = π52
A = 25π
A = πr2
A = π212
A = 441πA ≈ 50.27mm2
A ≈ 78.54in2 A ≈ 1,385.44cm2
![Page 9: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/9.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
Practice - Find the area. Round your answers to the nearest hundredth.
6.3 ft4 mm
1.
10cm
3. 2.
Find the Area of a Circle
A = πr2
A = π52
A = 25π
A ≈ 78.54cm2
A = πr2
A = π22
A = 4π
A ≈ 12.57mm2
A = πr2
A = π6.32
A = 39.69πA ≈ 124.69ft2
![Page 10: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/10.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
Practice - Find the circumference and area. Leave your answer in terms of π.
1. d = 6 cm 3. r = 5 in2. d = 18 mm
Find the Area and Circumference of a Circle
A = πr2
A = π32
A = 9π cm2
C = dπC = 6π cm
A = πr2
A = π92
A = 81π mm2
C = dπC = 18π mm
A = πr2
A = π52
A = 25π in2
C = dπC = 10π in
![Page 11: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/11.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
Find the radius of the circle when given the circumference.
C = 2∏r
1. C = 16 ∏ 2. C = 7 ∏ 3. C = 50 ∏
Find the Radius of the Circle given the Circumference
2∏r= 16 ∏2 2
∏r = 8∏∏ ∏
r = 8
2∏r= 7∏2 2
∏r = 3.5∏∏ ∏
r = 3.5
2∏r= 50∏2 2
∏r = 25 ∏∏ ∏
r = 25
![Page 12: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/12.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
Find the radius of the circle when given the circumference.
C = 2∏r
1. C = 10 ∏ 2. C = 44 ∏ 3. C = 200 ∏
Find the Radius of the Circle given the Circumference
2∏r= 10∏2 2
∏r = 5∏∏ ∏
r = 5
2∏r= 44∏2 2
∏r = 22 ∏∏ ∏
r = 22
2∏r= 200∏2 2
∏r = 100∏∏ ∏
r = 100
![Page 13: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/13.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
Jordan sews a lace border 42π inches long around the edge of a circular tablecloth?
What is the length of the radius from the inside edge of the lace to the center of the circular tablecloth?
42π
Find the Radius of the Circle given the Circumference
2∏r= 42∏2 2
∏r = 21 ∏∏ ∏
r = 21
C = 2∏r
The length of the radius is 21 inches long.
C = 42∏
![Page 14: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/14.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
A circular rug has a circumference of 6π feet. What is the radius of the rug?
Find the Radius of the Circle given the Circumference
2∏r= 6∏2 2
∏r = 3 ∏∏ ∏
r = 3
C = 2∏r
The radius of the rug is 3 feet.
C = 6∏
![Page 15: Aim: How do we find the circumference and area of a circle? 7G1 7G1 Calculate the radius or diameter, given the circumference or area of a circle. Do Now:](https://reader030.fdocuments.us/reader030/viewer/2022032611/56649ef35503460f94c05951/html5/thumbnails/15.jpg)
Aim: How do we find the circumference and area of a circle?
7G1 Calculate the radius or diameter, given the circumference or area of a circle.
The circumference of the circle below is 25.12 centimeters. (2006)
What is the best estimate for the length of the radius of the circle?a) 3 centimetersb) 4 centimetersc) 8 centimetersd)16 centimeters
radius
2∏r= 25.122 2
∏r = 12.56
3.14 3.14
r = 4
C = 2∏rC = 25.12
3.14r= 12.56