Circles
What is the formula for the circumference of a circle
2\pi r
A teacher is planning to cover a box with wrapping paper for a project.
The teacher asks: “How much material do I need to cover the outside of the box?”
What is the teacher asking for?
Surface Area
Fill in the blank:
Volume is the amount of _______ an object takes up or can hold.
space
Is this the correct formula for the area of a circle:
2\pi r^2
NO
A cylinder has a radius of 3 cm and a height of 5 cm. What is the surface area of the cylinder?
150.72 cm2
A cylindrical container has a radius of 3 cm and a height of 12 cm.
What is the volume of the container ?
339.12 cm3
Ahmed is inviting his family and friends for a pizza party. Instead it purchasing multiple difference pizzas, he ordered a king size party pizza to feed his guests. The diameter of the pizza is 90 cm. What is the area of the pizza
A =6361.7 cm2
GG corporation is designing a closed cylindrical containter to hold juice. The container has a diameter of 12 cm and a height of 15 cm. They want to cover the entire outside surface of the container with a label. How much material is needed to cover the container?
791.28 cm2
A cylindrical pencil holder has a radius of 3 cm and a height of 12 cm.
339.12 cm cm3
A city is designing a circular walking park. The park has a radius of 15.5 meters. To encourage exercise, the city wants to place a path along the edge of the park, and people are encouraged to walk 3 full laps around it.
What is the total distance a person would walk if they complete 2 laps around the park?
194.8 meters
A cylinder has a diameter of 10cm and a height of 8 cm. What is the surface area of the cylinder?
408.2 cm2
A cylindrical can of paint has a diameter of 10 cm and a height of 8 cm.
628 cm3
A city is building a circular fountain in a park. The fountain has a diameter of 20 meters.
Around the fountain, they plan to install a decorative border that follows the exact edge of the circle. The cost of the border is $12 per meter.
Additionally, they want to place small lights every 2 meters along the border (including the starting point, but not double-counting the end).
(a) What is the total cost of installing the border?
(b) How many lights are needed?
a.) $754.00
b.) 32 lights
A cylindrical storage drum has a diameter of 10cm and a height of 18cm. The entire outside of the drum (including the top and bottom) will be covered.
a.) What is the total surface area of the drum?
b.) If the covering material costs $0.05 per cm2 what is the total cost to cover the drum?
a.) 722.2 cm2
b.) $36.11
A water bottle has a diameter of 12 cm and a height of 10cm.
a.) What is the volume of the bottle?
b.) If the water bottle is only filled to 75% of its total capacity, what is volume of the juice in the water bottle?
a.) 1131 cm3
b.)