Question

How can I find the radius of a balloon?

Answer 1

Is the balloon a perfect sphere?

Answer 2

Yes, I had to blow it up slightly bigger than my hand.

Answer 3

Measure the circumference as close as you can around the middle, try not to distort the balloon as you do this. Then solve for \[2 \pi r =\] for your measurement.

Answer 4

You could measure it by encircling it with a piece of string and then measure the string with a ruler to get your circumference.

Answer 5

oh okay so I got 48 centimeters would this cound as part of my circumference? How can I find the result of the formula you just gave me if I don't know the radius?

Answer 6

If the ballon is 48 cm around, that is the circumference. So\[2 \pi r = 48cm\]
Solve the equation for the radius r. You only have one variable r.

Do you know how to do this?

Answer 7

oh okay and no not really :/ sorry..

Answer 8

OK, π is about 3.14. so 2π is about 6.28. To solve for r divid each side by 2π. it cancels out on the left side leaving r, the radius and you divid 48cm by 2π, 6.28, to get the radius.

Answer 9

Your not doing algebra yet are you. You'll learn to solve equations then. The 2πr = the perimeter of a circle you'll get in geometry. Its all fun stuff.

Answer 10

I am learning but it's confusing for me I've never been good at math, as you can probably tell but thank you for the rest that helped!

Answer 11

I got around 7.64

Answer 12

for the radius