Answer:
y=50°
Step-by-step explanation:
if all triangles add up to 180° you would subtract the angle you already know(80) from 180 which would be 100°
since there are 2 corners we dont know you would divide by 2 which would be 50°
A
(y-5) / (7-5) = (x-1) / (2-1)
(y-5) / 2 = x-1
y-5 = 2x -2
y = 2x +3
3
change 1 to an improper fraction
1 = , thus
× = = 3 or 3.57 ( to 2 dec. places )