Presentation on theme: "5 th Grade Miss Camerons Class. The circumference of a circle is The distance around a circle Hint: Circumference remember circle around. Circumference."— Presentation transcript:
5 th Grade Miss Camerons Class
The circumference of a circle is The distance around a circle Hint: Circumference remember circle around. Circumference is a circles perimeter.
The diameter is the distance across a circle through the center.
Vocabulary. The radius is the distance from the center of a circle to any point on a circle. Hint: It is ½ the diameter
We use Pi as the measurement to help us find the circumference of a circle. Pi, not Pie!
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.
Circumference = 2r When the radius of a circle is given, the following formula should be used. 2 x 5cm x cm HINT: You may round to the nearest tenth
NOW…Lets have some fun. Tell me what formula would be used to solve the next five problems.
3in C = 2 x r x 3.14
8ft C = 3.14 d
122mm C = 2 x r x 3.14
17.5 cm C = 3.14 x d
122.5mm C = 2 x r x 3.14
Now that we have determined the correct formula for each, lets work the problems.
3in C = 2 x 3.14 x r The answer is: 18.8in
8ft C = 3.14 d The answer is: 25.1ft
122mm C = 2 x 3.14 x d The answer is: 766.2mm
17.5 cm C = 3.14 x d The answer is: 55cm
122.5mm C = 2 x 3.14 x r The answer is: 76,930mm
r ² 6 m
Another formula ½ d x 12 ft
Find area 9 ft
Find area 15 mm
Find area 13 cm
Find area 19 ft
Circles rap By Miss Cameron Circles, those tricky circles! Pow! I said those circles. Those tricky circles! Pow!
Circumference is perimeter; its all the same They just try to trick you with a name game. Circumference is diameter, the length across Multiplied by pi So dont get lost
Pi is 3.14, a funny number. Rap with me now, & please dont slumber. Area for a circle is radius squared. So half the diameter and make it squared.
Well you know what to do, so do it now. Find circumference and area of a circle. POW! Circles, those tricky circles. POW! I said those circles, those tricky circles. POW!