Formulas
What is the formula for the circumference of a circle?
C = 2πr or C = πd
Find the area of a circle with a radius of 3.
28.26
What is the circumference of a circle with a radius of 4
25.12
Sarah used the formula for the area of a circle but mistakenly wrote it as A = πr. What did she do wrong?
Sarah forgot to square the radius in the area formula.
What is the most popular type of pie in the U.S.?
Apple pie
What is the formula for the area of a circle?
A = πr²
Find the area of a circle with a diameter of 10.
78.5
A circle has a diameter of 12. What is its circumference?
37.68
James calculated the circumference of a circle with a radius of 4 as C = 4π. What did he do wrong?
James forgot to multiply the radius by 2. The formula for circumference is C = 2πr
What holiday is most associated with eating pumpkin pie?
Thanksgiving
How do you find the diameter when given the radius
d = 2r
If the area of a circle is 16π, what is its radius?
r = 4
A bike tire has a circumference of 62.8 inches. What is its diameter? (must give unit of measurement)
d = 20 in
Emily tried to find the area of a circle with a diameter of 10 using the formula A = πd². What did she do wrong?
Emily used the diameter in place of the radius. The correct formula is A = πr², and the radius is half the diameter
What type of pie is made with a graham cracker crust, lime juice, and sweetened condensed milk
Key lime pie
How do you find the radius when given the diameterr = d/2
r = d/2
What is the area of a circle with a diameter of 7?
38.48
A Ferris wheel has a circumference of 157 meters. What is its radius? (must give unit of measurement)
r ≈ 25 m
Kevin used the value of 3 for pi to calculate the circumference of a circle with a radius of 5. What did he do wrong?
Kevin should have used 3.14 for pi, not just 3. The more accurate value of pi is 3.14, not 3
What country is credited with inventing the first known version of a pie? It is also known for its pyramids
Egypt
What are the first seven digits of pi
3.14159
A circular pond has an area of 314 square meters. What is the approximate radius of the pond? (Must give unit of measurement)
r = 10 m
A circular track has a radius of 15 meters. If an athlete runs around the track 3 times, what is the total distance traveled? (must give unit of measurement)
282.6 meters
Lily was calculating the circumference of a circle with a radius of 12 and said the answer was 452.12. What did she do wrong?
Lily used the wrong formula. The correct formula for circumference is C = 2πr, so it should have been C = 2 × 3.14 × 12 = 75.36.
What is the name of the famous dessert pie made with a filling of lemon juice, egg yolks, and sweetened condensed milk, typically served with a meringue topping?
Lemon meringue pie