What is the circumference of a circle with diameter 5 inches?

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Answer 1 · 2017-05-10T20:52:44

# C = 5pi ~~ 15.708 # inches (3 dp)

The circumference of a circle is given by:

# C = 2pir#

Where #r# is the radius, or equivalently

# C = pid #

Where #d=2r# is the diameter.

So, if the diameter is 5 inches then the circumference is:

# C = 5pi ~~ 15.708 # inches (3 dp)

Answer 2 · 2017-05-10T21:18:08

Exact circumference = #2pi2.5# in.

The formula for the circumference of a circle is:

#C=2pir#,

where #C# is circumference, #pi# is 3.1415..., and #r# is the radius.

#r=d/2#, where #d# is diameter.

Calculate the diameter.

#r=(5color(white)(.)"in")/2#

#r=2.5color(white)(.)"in"#

Calculate circumference.

#C=2pir#

#C=2xxpixx2.5color(white)(.)"inches"# or #2pi2.5color(white)(.)"inches"# #lArr# This is the exact circumference.

#C=2xxpixx2.5"in"~~15.7color(white)(.)"in"# #lArr# This is an approximate circumference because it is rounded off.