A right triangle is 90 degrees.
So 2/3 of a right triangle (90 degrees) is 60 degrees. This means the angle is 60 degrees.
To convert to radians multiply 60 degrees by pi/180 degrees.
Do this because you want to cancel out degrees by multiplying 60 with a fraction that has degrees in its denominator.
All that's left then is (60*pi)/180. Put this into your calculator and get 1.04719755, so approx 1.05 rounded to the hundredths or 2 decimal places. You can also leave it as 60pi/180 if allowed.
