12:00 AM
Try standard texts, like Hardy-Wright.

@BalarkaSen Yeah, but at first, she was a Number theorist.
I don't know, what leaded her to Geo

books by people who become geometer after studying number theory are most dangerous for health.

$$\int_{0}^{\frac{\pi}{2}} \dfrac{\log (\sec (x))}{\tan (x)} \text{ d}x = -\int_{0}^{\frac{\pi}{2}} \dfrac{\log(\cos(x)) \cdot \cos (x)}{\sin(x)} \text{ d}x$$

she is a hard-core hyperbolic geometer. sheeesh.

@robjohn When do you get Field Medal?

12:03 AM
i gotta run. need some serious sleep.

@BalarkaSen Bye, good night

@BalarkaSen Peace out, man!

12:27 AM
@MrWho He is too old to get it.

@JasperLoy Really?
@JasperLoy He has the potential, though.

@MrWho Just draw a circle with centre at the point the angle is formed. Then consider the ratio of the arc subtended by the angle and the circumference of the circle. Multiply this by 360 degrees and you get your angle. This is independent of the radius of the circle.

@JasperLoy How did they understand that the degree of the circle is $360$, why not $400$?

12:49 AM
There is no way to really "understand" a choice made by convention, you just get used to it :-)

1:09 AM
@skullpatrol I knew it is a convention, wanted to be sure.

1:41 AM
@MrWho there is a system called gradians where the circle is divided into 400ths, but most people use the standard 360 degrees.