Pi not PIE
What number are we using to represent pi?
3.14
The distance from the center of a circle to a point
radius
The formula for finding the circumference of a circle
Circumference=pi x diameter
or C= 3.14 x d
The formula for finding the Area of circle
A = Pi x r x r
or Pi r2
What is Mrs. Lippincott's favorite hour (class)?
This one!
True
The distance around a circle
If you are given the radius on a circle is 3, what is the first thing you need to do to find the circumference?
multiply the radius by 2 (3 x 2)
or
add the radius to itself to find the diameter (3 + 3)
The diameter of a tire is 20 inches. What is the area?
A = 314 inches2
If the area of a circle is 314 inches2 , what is the radius?
10 inches
Which of the following is equal to pi?
a. C x d
b. C divided by d
c. d divided by C
d. d-C
b. C divided by d
The distance from one point ON the circle, through the center to the other side of the circle.
If a bike tire has a diameter of 20 inches, what is the circumference?
62.8 inches
The radius of a circle is 10.25. What is the Area?
329.9 inches2
or
330 inches2
If the diameter of a cake is 44cm, the circumference is 138.16cm. What would the perimeter of HALF of the cake be?
113 cm
How long does pi go on after the decimal?
forever
it never repeats
The total space inside a flat shape.
Area
If a cake has a diameter of 44 centimeters, what is the circumference?
138 cm
A circle has a diameter of 50 ft. What is the area?
(Hint: find the radius first)
1,963 ft2
The area of a helicopter pad is 1,963 ft2. What is the radius?
25 feet
a. A/2r
b. C/d
c. d/C
d. r/2A
b C/d
The ratio of the circumference of a circle to the diameter
pi or 3.14
If a circle has a radius of 10.25 inches, what is the circumference?
64.4 inches
HALF of a circle has a radius of 9.5 inches. What is the area of the HALF circle (moon)?
141.69 in2
or
142 in2
A circle has an area of 616 m2 . What is the radius?
(hint: divide by pi first)
14 meters