5. The addition of the 3 internal angles of a triangle is equal to 180°, then
x° + 43° + 75° = 180°
x° = 180° - 43° - 75°
x = 62°
6. angle x and angle y are supplementary, then
x° + y° = 180°
Replacing with the value found for x,
62° + y° = 180°
y° = 180 - 62
y = 118°
7. angle y and angle z are opposite, then
y = z
as was stated before,
x + y = 180° or y + x = 180
angle x and angle z are supplementary, then
x + z = 180°
