In order to graph a polar graph you need to use the theta graph table.
r=a sinnθ The a is the maximum radius. The n tells you how many petals your graph has. Here is a video on How to graph roses.
Here's an example of a rose graph:
r = 3 sin(2θ)
As you can see the 3 in front of the sin shows the maximum amount of radius which is 3. The pedals are 2 because when the pedals are an even number it doubles. For example,when a graph has 6 graphs the coefficient of theta would be three.