So, this is going to be equal to three is equal to negative 20 times sine of theta of t times the derivative of theta with respect to time. So, how do we figure out what sine of theta of t is going to be? Well, let's just use that other information they gave us, and I'm gonna scroll down a little bit, get a little bit more real estate. So, sine of theta, let me write it over here, sine of theta at time t sub naught, that's what we care about, t is equal to t sub naught, what's that going to be? Well, sine is opposite over hypotenuse, so that's going to be y at t sub naught over our hypotenuse of 20 meters. Well, that's going to be equal to, that's going to be equal to, they tell us y of t sub naught is 15 meters over 20 meters, which is the same thing as 3 4ths. So, by this yellow information, they actually told us that this right over here is going to be equal to 3 4ths.