Design exercise ICL8038

Hi
I am at Stow college in glasgow doing an hnc in electronics
I have been asked to submit a report detailing how to calculate the resistance values to produce a triangular waveform with a duty cycle of 66.67% and a period of 30ms for an ICL3038 function generator.
I have the data sheets but am unsure how to begin

Any help would be appreciated

https://www.electro-tech-online.com/custompdfs/2005/05/FN2864.pdf
This is just a guess,
You just use the equations given. (top of page 5 in the link I provided)
you let t1=.66 (66% duty cycle), and t2=.33, and f=1/.030 (30 ms period). Giving you 3 equations and 3 unknowns (Ra, Rb, and C)
Then Just solve for your unknown resistor values.
Looks like it will get kinda messy.

I wish I got to do hands on stuff like this in my EE classes instead of all theory stuff.