Question

height of circle20cm circumference 200cm find radius

Answer 1

There is no height of circle but i think u are talking abt cylinder so

22/7 × r2 × 20 = 200
r2= 70/22
r = √70/22

Answer 2

Hey Friend

I hope there is a mistake in the question , it may be like this -" Circumference of a circle is 200 cm , find radius "
or
" Height of a cylinder is 20 cm and circumference is 200 cm . Find its Radius "

Your answer is $Circumference of a circle = 2 \pi r$
We need to find the Radius i.e 'r'
Here, Circumference = 200 cm 

So , 

$200= 2* \frac{22}{7}*r$
$r = \frac{200*7}{22*2}$
$r= \frac{350}{11}$
$r= 31.81 cm$

hope it helps