Respuesta :

The first angle would be 40 degrees.
All angles in a triangle add up to 180 degrees. (keep that in mind)

(this took me forever, btw)

The first angle would be 32.

32*2= 64

64+20= 84

32+64+84= 180

The key is to find the range in which the number could be derived from.

I hope this helped!