pls help will give brainliest and only put 1 variable in it ty

Answer:
(2/3)r=30
r=45cm
Step-by-step explanation:
When trying to find a fraction of something, multiply to get your answer:
(2/3) of r = (2/3)r
The blue ribbon can be represented by both 30cm and (2/3)r cm:
(2/3)r=30
2r=90
r=45cm