Charlie measured the circle-shaped part of a sun his sister drew on the chalkboard. The circumference of the circle is 62.8 cm. What is the diameter? (Use 3.14 for .)
+11912 so we would solve this like:
out here we are using the formula to find the circumference , to find the radius becoz radius id double of the diameter so if we find the radius , we can multiply if with 2 to get the diameter so here we go
Circumference=2*pi*r (now we will put 62.8 as circumference , 3.14 as pi and as we dont know radius we will assume it as r)
62.8 = 2 * 3.14 * r
62.8 = 6.28 * r
62.8 = 6.28r
r = 62.8 / 6.28 ( now deviding them both will give us our radius)
r = 10cm
So now we've got our radius as 10cm and so we will multiply it by 2 to get our diameter !
10 * 2 = 20 DIAMETER
Now we have got our answer or diameter which is 20cm!
I hope you've understood by now but if not then pls be free to ask!
i hope this helps!
and if you want to check that the answer is correct or not then you can put radius as 10 in its place and solve to get the circumference using the same formula i told u!
+11912 so we would solve this like:
out here we are using the formula to find the circumference , to find the radius becoz radius id double of the diameter so if we find the radius , we can multiply if with 2 to get the diameter so here we go
Circumference=2*pi*r (now we will put 62.8 as circumference , 3.14 as pi and as we dont know radius we will assume it as r)
62.8 = 2 * 3.14 * r
62.8 = 6.28 * r
62.8 = 6.28r
r = 62.8 / 6.28 ( now deviding them both will give us our radius)
r = 10cm
So now we've got our radius as 10cm and so we will multiply it by 2 to get our diameter !
10 * 2 = 20 DIAMETER
Now we have got our answer or diameter which is 20cm!
I hope you've understood by now but if not then pls be free to ask!
i hope this helps!
and if you want to check that the answer is correct or not then you can put radius as 10 in its place and solve to get the circumference using the same formula i told u!
+118723 Ok Rosala I have looked at this question for you.
Anonymous's answer is incorrect. It was correct up to the last line but then I think the answer was read off the calculator incorrectly.
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You answer is correct except that you have introduced a little error by saying that pi=3.14
This is just a 2 decimal place approximation for pi. if you had used pi from the calculator then your answer would not have been 20cm. It would have been 19.0999cm correct to 4 decimal places. OR 19cm correct to the nearest whole number.
Anyway the only error in your solution is rounding error.
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So yes I will certainly give your well earned 3 points. CPhill must have given you the original 3 points or I would not be able to do this.
+3454 Just an fyi Melody, it did say to use 3.14 for pi. :)
It's a good thing to remember though, I remember you pointing the same thing out to me and now I won't forget it!
