A Capybara needs to get from point A to point B around a circular pool (see diagram). If the Capybara swims half as fast as he can run, what angle should he jump in the pool to minimize the total travel time?

I know that to minimize time traveling you need to find the equation for time then derive and set to zero.

So far I have that time swimming = 2t, time running = t, speed = distance/time

I know that distance traveled on land is r*theta, but I have no idea how to find the distance traveled in water.

Right now my equation is Time spent traveling = r*theta*t + (Distance traveled in water)*2t

How can I find distance traveled by water? And is the rest of what I have done right?