http://www.ck12.org Chapter 10. Perimeter and Area
2.
- An extra large pizza has a diameter of 20 inches and is cut into 12 pieces. Find the length of the crust for one
piece of pizza.
Answers:
- Use the Arc Length formula.
PQ̂=^135
360
· 2 π( 12 )
PQ̂=^3
8
· 24 π
PQ̂= 9 π
- Use the Arc Length formula.
PQ̂=^360 −^260
360
· 2 π( 144 )
PQ̂=^5
18
· 288 π
PQ̂= 80 π
- The entire length of the crust, or the circumference of the pizza, is 20π≈ 62. 83 in. In 121 of the pizza, one piece
would have^6212.^83 ≈ 5 .24 inches of crust.
Practice
Find the arc length ofPQ̂in
⊙
A. Leave your answers in terms ofπ.
1.
2.
3.
4.
FindPA(the radius) in
⊙
A. Leave your answer in terms ofπ.
5.
6.
7.
Find the central angle ormPQ̂in
⊙
A. Round any decimal answers to the nearest tenth.
8.
9.
10.
- The Olympics symbol is five congruent circles arranged as shown below. Assume the top three circles are
tangent to each other. Brad is tracing the entire symbol for a poster. How far will his pen point travel?