A sphere with a radius of 2 cm has a surface area of
- 8pi cm^2.
- 16pi cm^2.
- 64pi cm^2.
Explanation from PART66Online
The surface area of a sphere is 4*pi*r squared. With a radius of 2 cm, r squared is 4, so the area is 4*pi*4 = 16*pi square centimetres. The 64*pi result mistakenly uses the volume idea or cubes the radius instead of squaring it.
S
syafinaz9092 asked · 17 Jan 2015
somebody can explain? thanks
Community Comments (1)
D
Dsutt0n
2 Apr 2015
Hi,
The equation for the area of a sphere is - A = 4Ï€r^2
So for this equation we have the radius of 2.
Therefor 2^2 = 4 x 4 = 16Ï€
The π is a symbol for pie and does not require you to work it out.
The equation for the area of a sphere is - A = 4Ï€r^2
So for this equation we have the radius of 2.
Therefor 2^2 = 4 x 4 = 16Ï€
The π is a symbol for pie and does not require you to work it out.
Please Sign In to post a comment.
More discussions in 1. Mathematics
- A sphere with a radius of 2 cm has a surface area of
- In a flight control system, the control cable is allowed an elongation of 3% due to wear. The length from the manufacturer is 78cm, what is its maximum used length?
- You have made 20% profit. Your balance is now 900 british pounds. What was your pre-profit balance?
- One of the square roots of a positive number is positive. What is the other one?
- A cylinder has a radius of 20cm and a length of 40cm. What is its volume? (Take pi as 3.1)
- The process of removing roots from the denominator of fractions is called what?