Download presentation

Presentation is loading. Please wait.

Published byMia McCormack Modified over 3 years ago

1
6 th Grade SPI: Calculate with circumferences and areas of circles.

2
The circumference of a circle is The distance around a circle Hint: Circumference remember circle around

3
First we must define some things about a circle. The radius is the distance from the center of a circle to any point on a circle. Hint: I like to define it as halfway through!

4
The diameter is the distance across a circle through the center.

5
We use Pi as the measurement to help us find the circumference of a circle. Pi, not Pie!

6
HINT: Pi =3.14

7
Two formulas are used in finding the circumference of a circle. Circumference = d 3.14 x 4in. 12.6in. WHEN THE CIRCLE HAS A DIAMETER MEASUREMENT, USE THE FOLLOWING FORMULA. 4in.

8
Circumference = 2 r When the radius of a circle is given, the following formula should be used. 2 x 3.14 x 5cm 31.4cm HINT: Always round your answers to the nearest tenth.

9
NOW…Lets have some fun. Tell me what formula would be used to solve the next five problems.

10
3in C = 2 x 3.14 x r

11
8ft C = 3.14 d

12
122mm C = 2 x 3.14 x d

13
17.5 cm C = 3.14 x d

14
122.5mm C = 2 x 3.14 x r

15
Now that we have determined the correct formula for each, lets work the problems.

16
3in C = 2 x 3.14 x r The answer is: 18.8in

17
8ft C = 3.14 d The answer is: 25.1ft

18
122mm C = 2 x 3.14 x d The answer is: 766.2mm

19
17.5 cm C = 3.14 x d The answer is: 55cm

20
122.5mm C = 2 x 3.14 x r The answer is: 76,930mm

21

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google