We use $\pi = 180$ degree in radian and degree relation why we not use the value of $\pi = 3.14$ in degree and radian relation? confused
Radians are just a unit that we use to measure angles with. It's about 60 degrees. ($\approx57$)
Degrees are another unit used to measure angles. It is much smaller than a radian. Radians and degrees can be thought of like meters and inches.
And just like $39.4$ inches and $1$ meter represent the same length, $\pi$ (the number 3.14...) radians and 180 degrees represent the same angle. $\pi$ still represents the number 3.14... when dealing with radians. It is just set up so that that many radians and 180 degrees are equivalent.
Note the difference between
1 ) $\pi = 180°$
2 ) $\pi$ radians $= 180°$
1) is wrong.