What model? It only says please help me lol
If 1/6 of the pan was left and there were 2 pieces left you just need to set 1/6 equal to 2/some number, this allows you to say that 1/6=2/x --> x/6=2-->x=12.
My explanation might be a little poor since this becomes fairly fundamental later on but hopefully it helps.
AngleA= angle D
5x+2=87
5x=85
X=17
180-87-42=51
Angle C= angle F
3y=51
Y=17
