Answer:
123°
Step-by-step explanation:
The following property must be satisfied
m∠WVX = m arc WX / 2
m arc WX = 2*m∠WVX
m arc WX = 2*51°
m arc WX = 102°
The summation of the three arcs that compound the circle is equal to 360°
m arc WX + m arc XV + m arc WV = 360°
m arc XV = 360° - m arc WV - m arc WX
m arc XV = 360° - 135° - 102°
m arc XV = 123°
