Formulas
Radius/Diameter
Circumference
Area
Hodge Podge
100
The formula for finding the circumference of a circle
What is C = π x d (Pi times diameter)
100
The radius of a circle with a diameter of 9 cm
What is 4.5 cm
100
The circumference of a circle in terms of pi with a diameter of 70 units
What is 70π (70 times pi)
100
The area of a circle in terms of pi with a radius of 5 units
What is 25π (25 times pi)
100
Pi Day always falls on this day of the year
What is March 14 (3-14)
200
The formula we use to find the diameter of a circle given the radius
What is d = 2 x r (two times the radius)
200
The diameter of a circle with a radius of 15 in.
What is 30 in.
200
The circumference of a circle in terms of pi for a circle with a radius of 20.5 units
What is 41π (41 times pi)
200
The area of a circle in terms of pi with a diameter of 16 units
What is 64π (64 times pi)
200
Dividing the circumference of a circle by its diameter will always get you this
What is π (pi)
300
The formula we use to find the radius of a circle given the diameter
What is r = 1/2 x d (one half of the diameter)
300
The diameter of a circle with a radius of 1 mm
What is 2 mm
300
The circumference of a circle with a diameter of 14 in. (Use 3.14 for pi.)
What is 43.96 in.
300
What we do to the radius when finding the area of a circle
What is square the radius (radius x radius)
300
The first 8 digits of pi
What is 3.1415926
400
The formula we use to find the area of a circle
What is A = πr^2 (Pi times the radius squared)
400
The diameter of a circle with a circumference of 9π (9 x pi)
What is 9 units
400
The circumference of a circle with a radius of 9.5 ft. (Use 3.14 for pi.)
What is 59.66 ft.
400
The area of a circle with a radius of 6 in. (Use 3.14 for pi.)
What is 113.04 square in.
400
The circumference of a circle is defined as this
What is the distance around a circle
500
The symbol that will be in your answer when a question asks, "... in terms of pi."
What is π (pi)
500
The radius of a circle with a circumference of 4π (4 x pi)
What is 2 units
500
The diameter of a circle with a circumference of 34.54 mm
What is 11 mm
500
The area of a circle with a diameter of 17 yds. (Use 3.14 for pi.)
What is 226.865 square yds.
500
Pi Day, 2015 is special for this reason
What is the first 8 digits of pi correspond to the date and time. It only happens once every 100 years. (3.1415926 = March 14, 2015 9:26)
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