Hola,
I have a particular interest in art, so I enjoyed doing this exercise. Yet, I have to agree with David that this lesson was possibly more challenging than the AI level.
I needed to listen to the measurements several times because I was unfamiliar with the use of "veinte coma dos" for example. (Although, I should have guessed, since this is similar to the French use of a comma instead of a decimal point.) After the first measurement, I was able to understand the second one. A good learning experience for me. I am coming back to Spanish, and have a lot to review and much more to learn for the first time.
May I suggest that there is a link to a lesson about numbers with decimals?
Gracias y Saludos