Consider what radians are.
A complete circle is said to have 2pi radians (if anyone asks why then say that it's made to fit the system of unit circles, circumference c=2pir with r=unit means c=2pi making trigonometric equations easier)
Now, a complete circle is also 360^o.
So that means, 360^o=2pi^cl
I'm using a "l" here because we don't know how exactly they're related, but we know that they're directly related this way.
Rearrange the equation and we get l=360^o/{2pi^c
Now, we need to find the value of radians for a 1400^o. Let's say we already found that it equals this x^c (that "c" on top implies that the number we're talking about here is radians, you might have noticed the "o" on top of the degrees by now)
So that means 1400^o=x^cl, which can be re-written as l=1400^o/{x^c}
It seems like we got two equations for l, so let's equate the two, meaning we get
1400^o/{x^c}=360^o/{2pi^c}
Rearranging, I get
{1400^o*2pi^c}/360^o=x^c
Now, this is why I'm happy calculator exists, which means if you used one here, you'd get x^c=24.43460952792061^c, or more simply x^c=24.4346^c
Now, this is the number of radians we have. We're asked to say how many pi's are there (but not a lot of pies sadly).
Now, if I had three chocolate bars, and had to distribute them among 2 people(excluding me), how many would each person have? Well, each person would have 1.5 chocolate bars.
Same thing here, we'll divide the value of x^c we got with pi people (of course pi people can't exist. Three people? yes, 3.1415 people? That'd be interesting)
That means x^c=7.7777pi^c