rational vs. reasonable

Dear teacher:
Could you tell me what’s the difference between “rational” and “reasonable” please? Which one should I pick in the following sentence as in: Hi, July, you’re an adult now, learn to look at things in a rational/reasonable way.
Many thanks in advance.

‘Irrational’ is more extreme than ‘unreasonable’.

Rational: being in or characterized by full possession of one’s reason; sane; lucid
Reasonable: agreeable to reason or sound judgment.

So, “the thing you did is irrational” means “You must be crazy.You’re insane.”
while, “the thing you did is unreasonable” means “I can’t understand why you do that. Let’s have a talk about this.”
Is that correct?
Anyway, Many thanks.

Hi Ttq,

In your sentence probably ‘rational’ would be needed because the assumption is that that July has grown up and is now able to work things out in a thinking, rational way.

‘Reasonable’ has now come to mean ‘acceptable’ ‘fair’ and is often applied to a word suggesting that it is something that is moderate. You could say: The price you paid for the car was reasonable. It’s the sort of price that you would expect to pay today.