PLEASE HELPP! A cylinder has the volume of 1000 pi show with working that if the height = 20cm then the radius = 5 cm.

5^2 = 100

100 x 3.14 = 314

Now we multiply by 20 since it's the height.

314 x 20 = 6,280 cm^3 is your answer.

Formula of cylinder:

H x πr^2

Height x pi(3.14 or 22/7 depending what they tell you to use for pi) x radius being squared (your radius is half of your diameter or given radius).

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.