## Elementary Geometry for College Students (7th Edition)

$17^{\circ}$
m$\angle$TSW = m$\angle$TSU + m$\angle$USV + m$\angle$VSW m$\angle$TSW = (m$\angle$TSW - m$\angle$USW) + m$\angle$USV + (m$\angle$TSW - m$\angle$TSV) 61 = (61 - 40) + m$\angle$USV + (61 - 38) 61 = 122 - 78 + m$\angle$USV 61 = 44 + m$\angle$USV m$\angle$USV = $17^{\circ}$