You can&#x27;t just baldly assert that radians are just as easy to understand as degrees - clearly they require more effort to understand, from an intuitive point of view. 
It seems obvious to me why degrees are easier to handle than radians: 180 is an easier number to understand than pi.<p>People don&#x27;t instinctively understand why on earth they would use a measurement unit where &#x27;1&#x27; of the unit has no obvious purpose. What can you do with a 1 radian angle? It&#x27;s a bit less than the angle in an equilateral triangle. It&#x27;s too big for usefully measuring things - most angles you come across will be somewhere between 0 and 3 radians, which is just weird.<p>What&#x27;s that, you don&#x27;t use radians like that? You use &#x27;fractions of pi&#x27; radians? But my calculator can only approximate pi to 9 decimal places, so how does that help me?<p>It&#x27;s incredibly easy for people to intuit that a ninety degree angle is the same as a 30 degree angle plus a 60 degree angle. But it takes deeper intuition about fractions to figure out that a pi&#x2F;2 radian angle is the same as a pi&#x2F;6 radian angle plus a pi&#x2F;3 radian angle. People are not used to units of measure that are typically denominated with rational fractions of irrational numbers.