Show:
Circumference
Mixed
Word Problems
100
The formula for circumference is ______ or _______
πd or 2πr.
100
If d=5.5 m, find C.
C=17.3 m
100
The Earth has a diameter of 7926.41 miles. What is the circumference of the Earth to the nearest hundreth of a mile?
C=πd=7926.41π=24901.55 miles
200
If r=17 cm, what is the circumference in terms of π?
17 x 2 x π= 34π cm
200
If a circle is inscribed in a square with a perimeter of 24 cm, what is the circumference of the circle?
6π cm
200
A dog is tied to a wooden stake in a backyard. His leash is 3 meters long and he runs around in circles pulling the leash as far as it can go. What is the distance the dog runs in a full revolution with the leash taut?
r=3 m C=2πr=2 x 3π=18.85 The dog runs 18.85 meters
300
If C=314 cm, what is the diameter to the nearest centimeter?
About 100 cm
300
Mr. Falcone's pizza shop offers three sizes of pizza. The small, medium, and large pizzas have circumferences of 25.1 in, 31.4 in, and 37.7 inches. So if Joey wants to buy a pizza witha 12 inch diameter, which size pizza should be buy?
Joey would buy a large pizza with the 37.7 inch circumference.
300
A street that is 516 feet long is covered in snow. City workers are using a snowplow to clear the street. The snowplow has tires that are 3.5 feet in diameter. How many times does a tire on the snowplow have to turn traveling the length of the street?
C=πd=3.5π=11 516/11= about 47 times
400
If a circle has a diameter of 12 cm, what is its circumference in terms of π?
C=πd=12π
400
Judy's water bottle has a radius of 3 cm. She is at the movie theater and wants to put her water bottle in the cup holder. The cup holder has a circumference of 20.4 cm. What is the circumference of the water bottle and will it fit in the cup holder?
The circumference is 18.9, and yes it will fit in the cup holder.
400
Joey wants a circular tale so that 12 chairs, each 16 inches wide, can be placed around it with at least 8 inches between chairs. What should the diameter of the table be?
12 x 16 + 8 x 12=288 If C=πd, d=C/π d=C/π=288/π=91.67 in.
500
Each year, a tree adds a new ring to its trunk. If the average width of a ring is 1 cm, how old is a tree with a circumference of 158π?
C=πd=158π so d=158 cm. To get the number of rings, you have to divide it by 2 to get the radius (because each ring goes all the way around). 158/2=79 The tree is 79 years old.
500
If the diameter of the moon is 2200 miles, find the average speed in miles per hour Luna Crator needs to circumnavigated the moon is 46 days.
V= d/t C=πd=2200π= about 6911.5 miles 6911.5 mi/46 days x 1 day/24 h=3606 mi/h (by cross multiplication)
500
The spray from a spinning lawn sprinkler covers 625π square feet. What is the circumference of the circle the sprinkler is spraying?
A=πr^2= square root of 625=25 C=2πr=2π x 25=157.08 About 157 ft.