# 5th Grade Miss Cameron’s Class

## Presentation on theme: "5th Grade Miss Cameron’s Class"— Presentation transcript:

CIRCUMFERENCE 5th Grade Miss Cameron’s Class

The circumference of a circle is
The distance around a circle Hint: Circumference remember circle around. Circumference is a circle’s perimeter.

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

Hint: It is ½ the diameter
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.
WHEN THE CIRCLE HAS A DIAMETER MEASUREMENT, USE THE FOLLOWING FORMULA. Circumference = d 4in. 3.14 x 4in. 12.6in.

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

Tell me what formula would be used to solve the next five problems.
NOW…Let’s 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, let’s work the problems.

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

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

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

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

The amount of space inside.
Area of a circle= The amount of space inside. 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 Circles, those tricky circles! Pow! I said those circles.
By Miss Cameron Circles, those tricky circles! Pow! I said those circles. Those tricky circles! Pow!

Circumference is perimeter; it’s all the same
They just try to trick you with a name game. Circumference is diameter, the length across Multiplied by pi So don’t get lost

Rap with me now, & please don’t slumber.
Pi is 3.14, a funny number. Rap with me now, & please don’t 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!

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