What is that 130 degrees in radians?

2pi radians in a circle

1 circle=360
therefor
ratio and proporiton
parts/whole=130/360=xradians/2pi

130/360=xradians/2pi
13/36=xradians/2pi
times 72pi both sides
26pi=36xradians
divide both sides by 36
(13pi)/18=xradians

(13pi)/18 radians
aprox 2.2689280275927 radians

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle