Explanation:
angle YWX = angle YXW ...eqn 1
angle XYZ = angle WYX (0.5) = 15x...eqn 2
angle YXZ = angle YXW = 2x + 5...eqn 3
=> from eqn 1 and 3 we get...
angle YWX = 2x + 5 ...eqn 4
=> from eqn 2 we get
angle WYX = 2 × angle XYZ = 30x...eqn 5
a triangle has a total of 180deg,
=>angle WYX + angle YWX + angle YXW = 180deg
=> 30x + 2x +5 + 2x +5 = 180deg
=> 34x +10 =180deg
=> x = 5deg
subst x = 5deg in eqn 5, we get
angle WYX = 30 × 5 = 150deg