Sphere = 3-Dimensional Round Shape with All Surface Points Equidistant from Center
Basics
r = radius = distance from surface to center
d = diameter = distance all the way across sphere through its center
SA = Surface Area = area covering surface of sphere (measured in square units)
V = Volume = space occupied by sphere (measured in cubic units)
Formulas (Mathematics Formula Sheet)
SA = 4πr²
V = πr³
Formulas (NOT on Mathematics Formula Sheet)
r =
Question
A ball has a radius of 7 centimeters. What is its surface area?
Answer
196π square centimeters
Answer Process
SA = 4πr²
SA = 4 × π × 7² = 196π
Input | Display | Comment |
![]() |
blinker | clears screen |
4 × π × 7 ![]() |
4*π*7² | SA = 4πr² |
![]() |
196π | Answer |
Sphere |
Question
With reference to the question above, what is the surface area of the ball in decimal form?
Answer
615.7521601 square centimeters
Answer Process
See Toggle.
196π ⇔ 615.7521601
Input | Display | Comment |
![]() |
blinker | clears screen |
4 × π × 7 ![]() |
4*π*7² | SA = 4πr² |
![]() |
196π | |
![]() |
615.7521601 | Answer (Toggle) |
Sphere |
Question
With reference to the question above, what is the area of the sphere to the nearest tenth?
Answer
615.8 square centimeters
Answer Process
See Rounding.
615.7521601 → 615.8
Question
A ball has a diameter of centimeters. To the nearest tenth of a square centimeter, what is its surface area?
Answer
660.5 square centimeters
Answer Process
r =
r = =
SA = 4πr²
SA = =
= 660.5198554 after toggle = 615.8 after rounding
Input | Display | Comment |
![]() |
blinker | clears screen |
![]() ![]() ![]() × ![]() ![]() ![]() ![]() ![]() |
r =
|
|
![]() |
r | |
4 × π × ![]() ![]() ![]() ![]() |
4*π* |
SA = 4πr² |
![]() |
||
![]() |
660.5198554 | Answer (before rounding) |
Sphere |
Question
A ball has a radius of 7 centimeters. To the nearest hundredth of a cubic centimeter, what is its volume?
Answer
1436.76 cubic centimeters
Answer Process
V = πr³
V = x π x 7³ =
= 1436.75504 after toggle = 1436.76 after rounding
Input | Display | Comment |
![]() |
blinker | clears screen |
![]() ![]() ![]() × π × 7 ![]() |
V = |
|
![]() |
||
![]() |
1436.75504 | Answer (before rounding) |
Sphere |
Question
A ball has a diameter of centimeters. To the nearest hundredth of a cubic centimeter, what is its volume?
Answer
1596.26 cubic centimeters
Answer Process
r =
r = =
V = πr³
V = =
=1596.256317 after toggle = 1596.26 after rounding
Input | Display | Comment |
![]() |
blinker | clears screen |
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
r = |
|
![]() |
r | |
![]() ![]() ![]() ![]() ![]() ![]() |
V = |
|
![]() |
||
![]() |
1596.256317 | Answer (before rounding) |
Sphere |
Practice – Questions
1. A model globe has a radius of 6 inches. What is its surface area?
2. With reference to Question 1, what is the globe’s surface area to the nearest tenth?
3. A model globe has a diameter of inches. To the nearest tenth of a square inch, what is its surface area?
4. A model globe has a radius of 6 inches. To the nearest hundredth of a cubic inch, what is its volume?
5. A model globe has a diameter of inches. To the nearest hundredth of a cubic inch, what is its volume?
Practice – Answers
1. 144π square inches
2. 452.4 square inches
3. 471.4 square inches
4. 904.78 cubic inches
5. 962.51 cubic inches