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How do you do pi?

We just started pi at school in maths and I have understood NOTHING? Can you help me?

  1. Calculate the circumference: a) diameter: 10 cm b)dia.: 8 cm c) dia.: 2 m d)dia.: 23.6 cm e) radius: 5 cm f) rad.: 3.8 m

  2. A circle has a circumference of 6.28 m a) diameter: ? b) radius of the circle: ?

  3. Use pi=22/7 to calculate the circumference of cirles with these dimensions: a) diameter= 3 1/2 b) diameter= 1 3/4 c) raduis= 4 3/8 km

Thanks guys!

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Answer #1

well all you need is the formulas, then you can substitute in the numbers

to find the circumfrence using the diameter use: pi x D with radius, use: 2 x pi x r

so for question 1: pi x diameter, or 2 times pi times radius

for questions 2: pi x D = circumference. so, D = circumference / pi radius is half of diameter so radius = (circumference / pi) / 2 . which is the same as circumference / 2 x pi

question 3 is the same as the first question, just instead of using 3.142 or whatever as pi, you use 22/7. so it’s pi x D = 22/7 x D.

get it? not sure if I helped but that should be enough for you do finish your homework, I’m not going to do it all for you :) good luck

funmail me anytime if you need help with your maths, I’m a bit of a neek, haha

Answer #2

To find the circumfrence I’m pretty sure you take pi (3.14) multiplied by the diameter

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