Answer/Step-by-step explanation:
5. ✔️Exterior angle = angle outside the triangle = W
✔️Remote interior angle of the triangle to the exterior angle W = opposite angles to angle W which are X and Y
✔️m<X + m<Y = m<W (exterior angle theorem of a triangle)
✔️m<W + m<Z = 180° (linear pair/angles on a straight line)
6. m<6 = 115°
m<5 = 120°
✔️m<2 = 180° - m<5° (linear pair/angles on a straight line)
m<2 = 180° - 120°
m<2 = 60°
✔️m<3 = 180° - m<6° (linear pair/angles on a straight line)
m<3 = 180° - 115°
m<3 = 65°
✔️m<1 = 180° - (m<2 + m<3) (sum of triangle theorem)
m<1 = 180° - (60° + 65°)
m<1 = 55°
✔️m<4 = 180° - m<1 (linear pair/angles on a straight line)
m<4 = 180° - 55°
m<4 = 125°